diff --git a/tests/test_aliases/test_body_model_aliases.py b/tests/test_aliases/test_body_model_aliases.py
new file mode 100644
index 000000000..dc125a062
--- /dev/null
+++ b/tests/test_aliases/test_body_model_aliases.py
@@ -0,0 +1,597 @@
+from typing import List, Optional
+
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+from pydantic import BaseModel, Field
+
+from ..utils import needs_pydanticv2
+
+pytestmark = needs_pydanticv2
+
+
+app = FastAPI()
+
+# =====================================================================================
+# Pydantic model with Field(alias=...)
+
+# ------------------------------
+# required field
+
+
+class RequiredFieldAliasModel(BaseModel):
+    param: str = Field(alias="param_alias")
+
+
+@app.post("/required-field-alias", operation_id="required_field_alias")
+async def required_field_alias(body: RequiredFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_required_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/required-field-alias", json={"param": "123"})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_alias" in detail[0]["loc"]
+
+
+def test_required_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/required-field-alias", json={"param_alias": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_required_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["RequiredFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {"type": "string", "title": "Param Alias"}
+    }
+
+
+# ------------------------------
+# optional field
+
+
+class OptionalFieldAliasModel(BaseModel):
+    param: Optional[str] = Field(None, alias="param_alias")
+
+
+@app.post("/optional-field-alias", operation_id="optional_field_alias")
+async def optional_field_alias(body: OptionalFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_optional_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/optional-field-alias", json={"param": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/optional-field-alias", json={"param_alias": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_optional_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["OptionalFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {
+            "anyOf": [{"type": "string"}, {"type": "null"}],
+            "title": "Param Alias",
+        },
+    }
+
+
+# ------------------------------
+# list field
+
+
+class ListFieldAliasModel(BaseModel):
+    param: List[str] = Field(alias="param_alias")
+
+
+@app.post("/list-field-alias", operation_id="list_field_alias")
+async def list_field_alias(body: ListFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_list_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/list-field-alias", json={"param": ["123", "456"]})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_alias" in detail[0]["loc"]
+
+
+def test_list_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/list-field-alias", json={"param_alias": ["123", "456"]})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_list_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["ListFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {
+            "items": {"type": "string"},
+            "type": "array",
+            "title": "Param Alias",
+        }
+    }
+
+
+# ------------------------------
+# optional list field
+
+
+class OptionalListFieldAliasModel(BaseModel):
+    param: Optional[List[str]] = Field(None, alias="param_alias")
+
+
+@app.post("/optional-list-field-alias", operation_id="optional_list_field_alias")
+async def optional_list_field_alias(body: OptionalListFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_optional_list_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/optional-list-field-alias", json={"param": ["123", "456"]})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_list_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-alias", json={"param_alias": ["123", "456"]}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_optional_list_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["OptionalListFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {
+            "anyOf": [{"items": {"type": "string"}, "type": "array"}, {"type": "null"}],
+            "title": "Param Alias",
+        },
+    }
+
+
+# =====================================================================================
+# Pydantic model with Field(validation_alias=...)
+
+# ------------------------------
+# required field
+
+
+class RequiredFieldValidationAliasModel(BaseModel):
+    param: str = Field(validation_alias="param_val_alias")
+
+
+@app.post(
+    "/required-field-validation-alias", operation_id="required_field_validation_alias"
+)
+async def required_field_validation_alias(body: RequiredFieldValidationAliasModel):
+    return {"param": body.param}
+
+
+def test_required_field_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/required-field-validation-alias", json={"param": "123"})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_required_field_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/required-field-validation-alias", json={"param_val_alias": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_required_field_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["RequiredFieldValidationAliasModel"]
+    assert body_schema["properties"] == {
+        "param_val_alias": {"title": "Param Val Alias", "type": "string"},
+    }
+
+
+# ------------------------------
+# optional field
+
+
+class OptionalFieldValidationAliasModel(BaseModel):
+    param: Optional[str] = Field(None, validation_alias="param_val_alias")
+
+
+@app.post(
+    "/optional-field-validation-alias", operation_id="optional_field_validation_alias"
+)
+async def optional_field_validation_alias(body: OptionalFieldValidationAliasModel):
+    return {"param": body.param}
+
+
+def test_optional_field_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/optional-field-validation-alias", json={"param": "123"})
+    assert resp.json() == {"param": None}
+
+
+def test_optional_field_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-field-validation-alias", json={"param_val_alias": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_optional_field_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["OptionalFieldValidationAliasModel"]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "anyOf": [{"type": "string"}, {"type": "null"}],
+            "title": "Param Val Alias",
+        },
+    }
+
+
+# ------------------------------
+# list field
+
+
+class ListFieldValidationAliasModel(BaseModel):
+    param: List[str] = Field(validation_alias="param_val_alias")
+
+
+@app.post("/list-field-validation-alias", operation_id="list_field_validation_alias")
+async def list_field_validation_alias(body: ListFieldValidationAliasModel):
+    return {"param": body.param}
+
+
+def test_list_field_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/list-field-validation-alias", json={"param": ["123", "456"]})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_list_field_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/list-field-validation-alias", json={"param_val_alias": ["123", "456"]}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_list_field_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["ListFieldValidationAliasModel"]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "items": {"type": "string"},
+            "title": "Param Val Alias",
+            "type": "array",
+        },
+    }
+
+
+# ------------------------------
+# optional list field
+
+
+class OptionalListFieldValidationAliasModel(BaseModel):
+    param: Optional[List[str]] = Field(None, validation_alias="param_val_alias")
+
+
+@app.post(
+    "/optional-list-field-validation-alias",
+    operation_id="optional_list_field_validation_alias",
+)
+async def optional_list_field_validation_alias(
+    body: OptionalListFieldValidationAliasModel,
+):
+    return {"param": body.param}
+
+
+def test_optional_list_field_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-validation-alias", json={"param": ["123", "456"]}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_list_field_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-validation-alias",
+        json={"param_val_alias": ["123", "456"]},
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_optional_list_field_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"][
+        "OptionalListFieldValidationAliasModel"
+    ]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "anyOf": [{"items": {"type": "string"}, "type": "array"}, {"type": "null"}],
+            "title": "Param Val Alias",
+        },
+    }
+
+
+# =====================================================================================
+# Pydantic model with Field(alias=..., validation_alias=...)
+
+# ------------------------------
+# required field
+
+
+class RequiredFieldAliasAndValidationAliasModel(BaseModel):
+    param: str = Field(alias="param_alias", validation_alias="param_val_alias")
+
+
+@app.post(
+    "/required-field-alias-and-validation-alias",
+    operation_id="required_field_alias_and_validation_alias",
+)
+async def required_field_alias_and_validation_alias(
+    body: RequiredFieldAliasAndValidationAliasModel,
+):
+    return {"param": body.param}
+
+
+def test_required_field_alias_and_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post(
+        "/required-field-alias-and-validation-alias", json={"param": "123"}
+    )
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_required_field_alias_and_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/required-field-alias-and-validation-alias", json={"param_alias": "123"}
+    )
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_required_field_alias_and_validation_alias_by_validation_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/required-field-alias-and-validation-alias", json={"param_val_alias": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_required_field_alias_and_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"][
+        "RequiredFieldAliasAndValidationAliasModel"
+    ]
+    assert body_schema["properties"] == {
+        "param_val_alias": {"title": "Param Val Alias", "type": "string"}
+    }
+
+
+# ------------------------------
+# optional field
+
+
+class OptionalFieldAliasAndValidationAliasModel(BaseModel):
+    param: Optional[str] = Field(
+        None, alias="param_alias", validation_alias="param_val_alias"
+    )
+
+
+@app.post(
+    "/optional-field-alias-and-validation-alias",
+    operation_id="optional_field_alias_and_validation_alias",
+)
+async def optional_field_alias_and_validation_alias(
+    body: OptionalFieldAliasAndValidationAliasModel,
+):
+    return {"param": body.param}
+
+
+def test_optional_field_alias_and_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-field-alias-and-validation-alias", json={"param": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_field_alias_and_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-field-alias-and-validation-alias", json={"param_alias": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_field_alias_and_validation_alias_by_validation_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-field-alias-and-validation-alias", json={"param_val_alias": "123"}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_optional_field_alias_and_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"][
+        "OptionalFieldAliasAndValidationAliasModel"
+    ]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "anyOf": [{"type": "string"}, {"type": "null"}],
+            "title": "Param Val Alias",
+        }
+    }
+
+
+# ------------------------------
+# list field
+
+
+class ListFieldAliasAndValidationAliasModel(BaseModel):
+    param: List[str] = Field(alias="param_alias", validation_alias="param_val_alias")
+
+
+@app.post(
+    "/list-field-alias-and-validation-alias",
+    operation_id="list_field_alias_and_validation_alias",
+)
+async def list_field_alias_and_validation_alias(
+    body: ListFieldAliasAndValidationAliasModel,
+):
+    return {"param": body.param}
+
+
+def test_list_field_alias_and_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post(
+        "/list-field-alias-and-validation-alias", json={"param": ["123", "456"]}
+    )
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_list_field_alias_and_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/list-field-alias-and-validation-alias", json={"param_alias": ["123", "456"]}
+    )
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "Field required"
+    assert "param_val_alias" in detail[0]["loc"]
+
+
+def test_list_field_alias_and_validation_alias_by_validation_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/list-field-alias-and-validation-alias",
+        json={"param_val_alias": ["123", "456"]},
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_list_field_alias_and_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"][
+        "ListFieldAliasAndValidationAliasModel"
+    ]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "items": {"type": "string"},
+            "title": "Param Val Alias",
+            "type": "array",
+        },
+    }
+
+
+# ------------------------------
+# optional list field
+
+
+class OptionalListFieldAliasAndValidationAliasModel(BaseModel):
+    param: Optional[List[str]] = Field(
+        None, alias="param_alias", validation_alias="param_val_alias"
+    )
+
+
+@app.post(
+    "/optional-list-field-alias-and-validation-alias",
+    operation_id="optional_list_field_alias_and_validation_alias",
+)
+async def optional_list_field_alias_and_validation_alias(
+    body: OptionalListFieldAliasAndValidationAliasModel,
+):
+    return {"param": body.param}
+
+
+def test_optional_list_field_alias_and_validation_alias_by_name():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-alias-and-validation-alias",
+        json={"param": ["123", "456"]},
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_list_field_alias_and_validation_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-alias-and-validation-alias",
+        json={"param_alias": ["123", "456"]},
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_list_field_alias_and_validation_alias_by_validation_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-alias-and-validation-alias",
+        json={"param_val_alias": ["123", "456"]},
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_optional_list_field_alias_and_validation_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"][
+        "OptionalListFieldAliasAndValidationAliasModel"
+    ]
+    assert body_schema["properties"] == {
+        "param_val_alias": {
+            "anyOf": [{"items": {"type": "string"}, "type": "array"}, {"type": "null"}],
+            "title": "Param Val Alias",
+        },
+    }
diff --git a/tests/test_aliases/test_body_model_aliases_pd_v1.py b/tests/test_aliases/test_body_model_aliases_pd_v1.py
new file mode 100644
index 000000000..11df5d5c9
--- /dev/null
+++ b/tests/test_aliases/test_body_model_aliases_pd_v1.py
@@ -0,0 +1,170 @@
+from typing import List, Optional
+
+from fastapi import FastAPI
+from fastapi._compat import PYDANTIC_V2
+from fastapi.testclient import TestClient
+from pydantic import BaseModel, Field
+
+from ..utils import needs_pydanticv1
+
+pytestmark = needs_pydanticv1
+
+
+app = FastAPI()
+
+# =====================================================================================
+# Pydantic model with Field(alias=...)
+
+# ------------------------------
+# required field
+
+
+class RequiredFieldAliasModel(BaseModel):
+    param: str = Field(alias="param_alias")
+
+
+@app.post("/required-field-alias", operation_id="required_field_alias")
+async def required_field_alias(body: RequiredFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_required_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/required-field-alias", json={"param": "123"})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "field required"
+    assert "param_alias" in detail[0]["loc"]
+
+
+def test_required_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/required-field-alias", json={"param_alias": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_required_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["RequiredFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {"type": "string", "title": "Param Alias"}
+    }
+
+
+# ------------------------------
+# optional field
+
+if not PYDANTIC_V2:
+
+    class OptionalFieldAliasModel(BaseModel):
+        param: Optional[str] = Field(None, alias="param_alias", nullable=True)
+
+    @app.post("/optional-field-alias", operation_id="optional_field_alias")
+    async def optional_field_alias(body: OptionalFieldAliasModel):
+        return {"param": body.param}
+
+
+def test_optional_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/optional-field-alias", json={"param": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/optional-field-alias", json={"param_alias": "123"})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": "123"}
+
+
+def test_optional_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["OptionalFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {"nullable": True, "title": "Param Alias", "type": "string"}
+    }
+
+
+# ------------------------------
+# list field
+
+
+class ListFieldAliasModel(BaseModel):
+    param: List[str] = Field(alias="param_alias")
+
+
+@app.post("/list-field-alias", operation_id="list_field_alias")
+async def list_field_alias(body: ListFieldAliasModel):
+    return {"param": body.param}
+
+
+def test_list_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/list-field-alias", json={"param": ["123", "456"]})
+    assert resp.status_code == 422
+    detail = resp.json()["detail"]
+    assert detail[0]["msg"] == "field required"
+    assert "param_alias" in detail[0]["loc"]
+
+
+def test_list_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post("/list-field-alias", json={"param_alias": ["123", "456"]})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_list_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["ListFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {
+            "items": {"type": "string"},
+            "type": "array",
+            "title": "Param Alias",
+        }
+    }
+
+
+# ------------------------------
+# optional list field
+
+if not PYDANTIC_V2:
+
+    class OptionalListFieldAliasModel(BaseModel):
+        param: Optional[List[str]] = Field(None, alias="param_alias", nullable=True)
+
+    @app.post("/optional-list-field-alias", operation_id="optional_list_field_alias")
+    async def optional_list_field_alias(body: OptionalListFieldAliasModel):
+        return {"param": body.param}
+
+
+def test_optional_list_field_alias_by_name():
+    client = TestClient(app)
+    resp = client.post("/optional-list-field-alias", json={"param": ["123", "456"]})
+    assert resp.status_code == 200
+    assert resp.json() == {"param": None}
+
+
+def test_optional_list_field_alias_by_alias():
+    client = TestClient(app)
+    resp = client.post(
+        "/optional-list-field-alias", json={"param_alias": ["123", "456"]}
+    )
+    assert resp.status_code == 200
+    assert resp.json() == {"param": ["123", "456"]}
+
+
+def test_optional_list_field_alias_schema():
+    openapi = app.openapi()
+    body_schema = openapi["components"]["schemas"]["OptionalListFieldAliasModel"]
+    assert body_schema["properties"] == {
+        "param_alias": {
+            "items": {"type": "string"},
+            "nullable": True,
+            "title": "Param Alias",
+            "type": "array",
+        }
+    }