diff --git a/CHANGES/1232.bugfix b/CHANGES/1232.bugfix
new file mode 100644
index 000000000..d6eabc4a5
--- /dev/null
+++ b/CHANGES/1232.bugfix
@@ -0,0 +1 @@
+Fixed `upload_time` in Simple and JSON APIs to reflect repository addition time instead of content creation time.
diff --git a/pulp_python/app/pypi/views.py b/pulp_python/app/pypi/views.py
index 04bcc1653..b8585df7a 100644
--- a/pulp_python/app/pypi/views.py
+++ b/pulp_python/app/pypi/views.py
@@ -7,6 +7,7 @@
 from django.contrib.sessions.models import Session
 from django.core.exceptions import ObjectDoesNotExist
 from django.db import transaction
+from django.db.models import OuterRef, Subquery
 from django.db.utils import DatabaseError
 from django.http.response import (
     Http404,
@@ -25,6 +26,7 @@
 from rest_framework.response import Response
 from rest_framework.viewsets import ViewSet
 
+from pulpcore.plugin.models import RepositoryContent
 from pulpcore.plugin.tasking import dispatch
 from pulpcore.plugin.util import get_domain, get_url
 from pulpcore.plugin.viewsets import OperationPostponedResponse
@@ -366,13 +368,20 @@ def retrieve(self, request, path, package):
             return redirect(urljoin(self.base_content_url, f"{path}/simple/{normalized}/"))
         if content is not None:
             local_packages = content.filter(name_normalized=normalized)
-            packages = local_packages.values(
+            repo_added_subquery = RepositoryContent.objects.filter(
+                content_id=OuterRef("pk"),
+                repository=repo_ver.repository,
+                version_removed=None,
+            ).values("pulp_created")[:1]
+            packages = local_packages.annotate(
+                repo_added_time=Subquery(repo_added_subquery)
+            ).values(
                 "filename",
                 "sha256",
                 "metadata_sha256",
                 "requires_python",
                 "size",
-                "pulp_created",
+                "repo_added_time",
                 "version",
             )
             provenances = PackageProvenance.objects.filter(package__in=local_packages).values_list(
@@ -382,7 +391,7 @@ def retrieve(self, request, path, package):
                 p["filename"]: {
                     **p,
                     "url": urljoin(self.base_content_url, f"{path}/{p['filename']}"),
-                    "upload_time": p["pulp_created"],
+                    "upload_time": p["repo_added_time"],
                     "provenance": (
                         self.get_provenance_url(normalized, p["version"], p["filename"])
                         if p["filename"] in provenances
@@ -464,7 +473,11 @@ def retrieve(self, request, path, meta):
             if settings.DOMAIN_ENABLED:
                 domain = get_domain()
             json_body = python_content_to_json(
-                path, package_content, version=version, domain=domain
+                path,
+                package_content,
+                version=version,
+                domain=domain,
+                repository_version=repo_ver,
             )
             if json_body:
                 return Response(data=json_body, headers=headers)
diff --git a/pulp_python/app/utils.py b/pulp_python/app/utils.py
index 203a15300..1b30e82a4 100644
--- a/pulp_python/app/utils.py
+++ b/pulp_python/app/utils.py
@@ -11,6 +11,7 @@
 import pkginfo
 from aiohttp.client_exceptions import ClientError
 from django.conf import settings
+from django.db.models import OuterRef, Subquery
 from django.db.utils import IntegrityError
 from jinja2 import Template
 from packaging.requirements import Requirement
@@ -19,7 +20,7 @@
 from pypi_simple import ACCEPT_JSON_PREFERRED, ProjectPage
 
 from pulpcore.plugin.exceptions import TimeoutException
-from pulpcore.plugin.models import Artifact, Remote
+from pulpcore.plugin.models import Artifact, Remote, RepositoryContent
 from pulpcore.plugin.util import get_domain
 
 log = logging.getLogger(__name__)
@@ -359,7 +360,9 @@ def fetch_json_release_metadata(name: str, version: str, remotes: set[Remote]) -
         raise Exception(f"Failed to fetch {url} from any remote.")
 
 
-def python_content_to_json(base_path, content_query, version=None, domain=None):
+def python_content_to_json(
+    base_path, content_query, version=None, domain=None, repository_version=None
+):
     """
     Converts a QuerySet of PythonPackageContent into the PyPi JSON format
     https://www.python.org/dev/peps/pep-0566/
@@ -371,6 +374,13 @@ def python_content_to_json(base_path, content_query, version=None, domain=None):
 
     Returns None if version is specified but not found within content_query
     """
+    if repository_version:
+        repo_added_subquery = RepositoryContent.objects.filter(
+            content_id=OuterRef("pk"),
+            repository=repository_version.repository,
+            version_removed=None,
+        ).values("pulp_created")[:1]
+        content_query = content_query.annotate(repo_added_time=Subquery(repo_added_subquery))
     full_metadata = {"last_serial": 0}  # For now the serial field isn't supported by Pulp
     latest_content = latest_content_version(content_query, version)
     if not latest_content:
@@ -515,8 +525,10 @@ def find_artifact():
         "python_version": content.python_version,
         "requires_python": content.requires_python or None,
         "size": content.size,
-        "upload_time": str(content.pulp_created),
-        "upload_time_iso_8601": str(content.pulp_created.isoformat()),
+        "upload_time": str(getattr(content, "repo_added_time", None) or content.pulp_created),
+        "upload_time_iso_8601": str(
+            (getattr(content, "repo_added_time", None) or content.pulp_created).isoformat()
+        ),
         "url": url,
         "yanked": False,
         "yanked_reason": None,
diff --git a/pulp_python/tests/functional/api/test_pypi_apis.py b/pulp_python/tests/functional/api/test_pypi_apis.py
index 4934d3a98..48a3179d2 100644
--- a/pulp_python/tests/functional/api/test_pypi_apis.py
+++ b/pulp_python/tests/functional/api/test_pypi_apis.py
@@ -1,4 +1,6 @@
 import subprocess
+import time
+from datetime import datetime
 from urllib.parse import urljoin
 
 import pytest
@@ -6,6 +8,7 @@
 
 from pulp_python.tests.functional.constants import (
     PYPI_SERIAL_CONSTANT,
+    PYPI_SIMPLE_V1_JSON,
     PYTHON_EGG_FILENAME,
     PYTHON_EGG_SHA256,
     PYTHON_MD_PROJECT_SPECIFIER,
@@ -13,6 +16,8 @@
     PYTHON_WHEEL_FILENAME,
     PYTHON_WHEEL_SHA256,
     SHELF_PYTHON_JSON,
+    TWINE_WHEEL_FILENAME,
+    TWINE_WHEEL_URL,
 )
 from pulp_python.tests.functional.utils import ensure_metadata
 
@@ -328,3 +333,41 @@ def assert_download_info(expected, received, message="Failed to match"):
                 matched = True
                 break
         assert matched is True, message
+
+
+@pytest.mark.parallel
+def test_upload_time_reflects_repo_addition(
+    monitor_task,
+    python_bindings,
+    python_content_factory,
+    python_distribution_factory,
+    python_repo_factory,
+):
+    """
+    Test that upload_time reflects repository addition time instead of content creation time.
+    Checks both Simple and JSON APIs.
+    """
+    content = python_content_factory(TWINE_WHEEL_FILENAME, url=TWINE_WHEEL_URL)
+    content_created = datetime.fromisoformat(
+        str(python_bindings.ContentPackagesApi.read(content.pulp_href).pulp_created)
+    )
+    time.sleep(2)
+
+    repo = python_repo_factory()
+    body = {"add_content_units": [content.pulp_href]}
+    monitor_task(python_bindings.RepositoriesPythonApi.modify(repo.pulp_href, body).task)
+    distro = python_distribution_factory(repository=repo)
+
+    # Simple API
+    headers = {"Accept": PYPI_SIMPLE_V1_JSON}
+    resp = requests.get(f"{urljoin(distro.base_url, 'simple/')}twine", headers=headers)
+    assert resp.status_code == 200
+    simple_time = datetime.fromisoformat(resp.json()["files"][0]["upload-time"])
+    assert simple_time > content_created
+
+    # JSON API
+    json_resp = requests.get(urljoin(distro.base_url, "pypi/twine/json"))
+    assert json_resp.status_code == 200
+    json_time = datetime.fromisoformat(json_resp.json()["urls"][0]["upload_time"])
+    assert json_time > content_created
+    assert json_time == simple_time
diff --git a/pulp_python/tests/functional/api/test_pypi_simple_api.py b/pulp_python/tests/functional/api/test_pypi_simple_api.py
index c9e6b7dd8..7a7ff8660 100644
--- a/pulp_python/tests/functional/api/test_pypi_simple_api.py
+++ b/pulp_python/tests/functional/api/test_pypi_simple_api.py
@@ -5,6 +5,9 @@
 
 from pulp_python.tests.functional.constants import (
     PYPI_SERIAL_CONSTANT,
+    PYPI_SIMPLE_V1_HTML,
+    PYPI_SIMPLE_V1_JSON,
+    PYPI_TEXT_HTML,
     PYTHON_SM_FIXTURE_CHECKSUMS,
     PYTHON_SM_FIXTURE_RELEASES,
     PYTHON_SM_PROJECT_SPECIFIER,
@@ -27,10 +30,6 @@
 
 API_VERSION = "1.1"
 
-PYPI_TEXT_HTML = "text/html"
-PYPI_SIMPLE_V1_HTML = "application/vnd.pypi.simple.v1+html"
-PYPI_SIMPLE_V1_JSON = "application/vnd.pypi.simple.v1+json"
-
 
 @pytest.mark.parallel
 def test_simple_html_index_api(
diff --git a/pulp_python/tests/functional/constants.py b/pulp_python/tests/functional/constants.py
index d1b54ac2e..9cd052250 100644
--- a/pulp_python/tests/functional/constants.py
+++ b/pulp_python/tests/functional/constants.py
@@ -382,3 +382,7 @@
 ]
 
 PYPI_SERIAL_CONSTANT = 1000000000
+
+PYPI_TEXT_HTML = "text/html"
+PYPI_SIMPLE_V1_HTML = "application/vnd.pypi.simple.v1+html"
+PYPI_SIMPLE_V1_JSON = "application/vnd.pypi.simple.v1+json"