diff --git a/changelogs/fragments/67093-site-packages-pythonpath-collections-loader.yml b/changelogs/fragments/67093-site-packages-pythonpath-collections-loader.yml
new file mode 100644
index 00000000000..d1a669a855e
--- /dev/null
+++ b/changelogs/fragments/67093-site-packages-pythonpath-collections-loader.yml
@@ -0,0 +1,5 @@
+minor_changes:
+- >-
+  Enable Ansible Collections loader to discover and
+  import collections from ``site-packages`` dir and
+  ``PYTHONPATH``-added locations.
diff --git a/lib/ansible/utils/collection_loader.py b/lib/ansible/utils/collection_loader.py
index 2a70595aa2a..bf4d7589480 100644
--- a/lib/ansible/utils/collection_loader.py
+++ b/lib/ansible/utils/collection_loader.py
@@ -33,17 +33,33 @@ _SYNTHETIC_PACKAGES = {
 class AnsibleCollectionLoader(with_metaclass(Singleton, object)):
     def __init__(self, config=None):
         if config:
-            self._n_configured_paths = config.get_config_value('COLLECTIONS_PATHS')
+            paths = config.get_config_value('COLLECTIONS_PATHS')
         else:
-            self._n_configured_paths = os.environ.get('ANSIBLE_COLLECTIONS_PATHS', '').split(os.pathsep)
+            paths = os.environ.get('ANSIBLE_COLLECTIONS_PATHS', '').split(os.pathsep)
 
-        if isinstance(self._n_configured_paths, string_types):
-            self._n_configured_paths = [self._n_configured_paths]
-        elif self._n_configured_paths is None:
-            self._n_configured_paths = []
+        if isinstance(paths, string_types):
+            paths = [paths]
+        elif paths is None:
+            paths = []
 
         # expand any placeholders in configured paths
-        self._n_configured_paths = [to_native(os.path.expanduser(p), errors='surrogate_or_strict') for p in self._n_configured_paths]
+        paths = [
+            to_native(os.path.expanduser(p), errors='surrogate_or_strict')
+            for p in paths
+        ]
+
+        # Append all ``ansible_collections`` dirs from sys.path to the end
+        for path in sys.path:
+            if (
+                    path not in paths and
+                    os.path.isdir(to_bytes(
+                        os.path.join(path, 'ansible_collections'),
+                        errors='surrogate_or_strict',
+                    ))
+            ):
+                paths.append(path)
+
+        self._n_configured_paths = paths
 
         self._n_playbook_paths = []
         self._default_collection = None
diff --git a/test/integration/targets/collections_runtime_pythonpath/aliases b/test/integration/targets/collections_runtime_pythonpath/aliases
new file mode 100644
index 00000000000..0a772ad706c
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/aliases
@@ -0,0 +1,3 @@
+shippable/posix/group4
+skip/python2.6
+skip/aix
diff --git a/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/ansible_collections/python/dist/plugins/modules/boo.py b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/ansible_collections/python/dist/plugins/modules/boo.py
new file mode 100644
index 00000000000..a2313b127d2
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/ansible_collections/python/dist/plugins/modules/boo.py
@@ -0,0 +1,28 @@
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+"""Say hello."""
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    module = AnsibleModule(
+        argument_spec={
+            'name': {'default': 'world'},
+        },
+    )
+    name = module.params['name']
+
+    module.exit_json(
+        msg='Greeting {name} completed.'.
+        format(name=name.title()),
+        greeting='Hello, {name}!'.format(name=name),
+    )
+
+
+if __name__ == '__main__':
+    main()
diff --git a/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/pyproject.toml b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/pyproject.toml
new file mode 100644
index 00000000000..feec734a6b0
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/pyproject.toml
@@ -0,0 +1,6 @@
+[build-system]
+requires = [
+  "setuptools >= 44",
+  "wheel",
+]
+build-backend = "setuptools.build_meta"
diff --git a/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/setup.cfg b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/setup.cfg
new file mode 100644
index 00000000000..d25ebb0fc37
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-boo/setup.cfg
@@ -0,0 +1,15 @@
+[metadata]
+name = ansible-collections.python.dist
+version = 1.0.0rc2.post3.dev4
+
+[options]
+package_dir =
+    = .
+packages =
+    ansible_collections
+    ansible_collections.python
+    ansible_collections.python.dist
+    ansible_collections.python.dist.plugins
+    ansible_collections.python.dist.plugins.modules
+zip_safe = True
+include_package_data = True
diff --git a/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-foo/ansible_collections/python/dist/plugins/modules/boo.py b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-foo/ansible_collections/python/dist/plugins/modules/boo.py
new file mode 100644
index 00000000000..1ef033303b0
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/ansible-collection-python-dist-foo/ansible_collections/python/dist/plugins/modules/boo.py
@@ -0,0 +1,28 @@
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+"""Say hello in Ukrainian."""
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+from ansible.module_utils.basic import AnsibleModule
+
+
+def main():
+    module = AnsibleModule(
+        argument_spec={
+            'name': {'default': 'світ'},
+        },
+    )
+    name = module.params['name']
+
+    module.exit_json(
+        msg='Greeting {name} completed.'.
+        format(name=name.title()),
+        greeting='Привіт, {name}!'.format(name=name),
+    )
+
+
+if __name__ == '__main__':
+    main()
diff --git a/test/integration/targets/collections_runtime_pythonpath/runme.sh b/test/integration/targets/collections_runtime_pythonpath/runme.sh
new file mode 100755
index 00000000000..e1f2574815b
--- /dev/null
+++ b/test/integration/targets/collections_runtime_pythonpath/runme.sh
@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+
+set -eux -o pipefail
+
+
+export PIP_DISABLE_PIP_VERSION_CHECK=1
+
+
+source virtualenv.sh
+
+
+>&2 echo \
+    === Test that the module \
+    gets picked up if discoverable \
+    via PYTHONPATH env var ===
+PYTHONPATH="${PWD}/ansible-collection-python-dist-boo:$PYTHONPATH" \
+ansible \
+    -m python.dist.boo \
+    -a 'name=Bob' \
+    -c local localhost \
+    "$@" | grep -E '"greeting": "Hello, Bob!",'
+
+
+>&2 echo \
+    === Test that the module \
+    gets picked up if installed \
+    into site-packages ===
+python -m pip.__main__ install pep517
+( # Build a binary Python dist (a wheel) using PEP517:
+  cp -r ansible-collection-python-dist-boo "${OUTPUT_DIR}/"
+  cd "${OUTPUT_DIR}/ansible-collection-python-dist-boo"
+  python -m pep517.build --binary --out-dir dist .
+)
+# Install a pre-built dist with pip:
+python -m pip.__main__ install \
+  --no-index \
+  -f "${OUTPUT_DIR}/ansible-collection-python-dist-boo/dist/" \
+  --only-binary=ansible-collections.python.dist \
+  ansible-collections.python.dist
+python -m pip.__main__ show ansible-collections.python.dist
+ansible \
+    -m python.dist.boo \
+    -a 'name=Frodo' \
+    -c local localhost \
+    "$@" | grep -E '"greeting": "Hello, Frodo!",'
+
+
+>&2 echo \
+    === Test that ansible_collections \
+    root takes precedence over \
+    PYTHONPATH/site-packages ===
+# This is done by injecting a module with the same FQCN
+# into another collection root.
+ANSIBLE_COLLECTIONS_PATHS="${PWD}/ansible-collection-python-dist-foo" \
+PYTHONPATH="${PWD}/ansible-collection-python-dist-boo:$PYTHONPATH" \
+ansible \
+    -m python.dist.boo \
+    -a 'name=Степан' \
+    -c local localhost \
+    "$@" | grep -E '"greeting": "Привіт, Степан!",'