diff --git a/changelogs/fragments/galaxy-build-files-ignore.yml b/changelogs/fragments/galaxy-build-files-ignore.yml
new file mode 100644
index 00000000000..983307e0ceb
--- /dev/null
+++ b/changelogs/fragments/galaxy-build-files-ignore.yml
@@ -0,0 +1,4 @@
+bugfixes:
+- >-
+  ansible-galaxy collection build - Ignore any existing ``MANIFEST.json`` and ``FILES.json`` in the root directory
+  when building a collection.
diff --git a/lib/ansible/galaxy/collection.py b/lib/ansible/galaxy/collection.py
index 054a8a57b50..3ef71172c55 100644
--- a/lib/ansible/galaxy/collection.py
+++ b/lib/ansible/galaxy/collection.py
@@ -931,6 +931,8 @@ def _build_files_manifest(b_collection_path, namespace, name, ignore_patterns):
     # We always ignore .pyc and .retry files as well as some well known version control directories. The ignore
     # patterns can be extended by the build_ignore key in galaxy.yml
     b_ignore_patterns = [
+        b'MANIFEST.json',
+        b'FILES.json',
         b'galaxy.yml',
         b'galaxy.yaml',
         b'.git',