diff --git a/changelogs/fragments/12140-filetree-exclude-regex-error.yml b/changelogs/fragments/12140-filetree-exclude-regex-error.yml
new file mode 100644
index 0000000000..6608ceb3c1
--- /dev/null
+++ b/changelogs/fragments/12140-filetree-exclude-regex-error.yml
@@ -0,0 +1,2 @@
+bugfixes:
+  - filetree lookup plugin - raise ``AnsibleLookupError`` when the ``exclude`` option contains an invalid regular expression instead of an uncaught ``re.error`` (https://github.com/ansible-collections/community.general/pull/12140).
diff --git a/plugins/lookup/filetree.py b/plugins/lookup/filetree.py
index 53f43b39cb..365fea1b6c 100644
--- a/plugins/lookup/filetree.py
+++ b/plugins/lookup/filetree.py
@@ -142,6 +142,7 @@ try:
 except ImportError:
     pass
 
+from ansible.errors import AnsibleLookupError
 from ansible.module_utils.common.text.converters import to_native, to_text
 from ansible.plugins.lookup import LookupBase
 from ansible.utils.display import Display
@@ -223,7 +224,13 @@ class LookupModule(LookupBase):
 
         # Regular expression for exclude
         exclude = self.get_option("exclude")
-        exclude_pattern = re.compile(exclude) if exclude else None
+        if exclude:
+            try:
+                exclude_pattern = re.compile(exclude)
+            except re.error as e:
+                raise AnsibleLookupError(f"Invalid exclude regular expression {exclude!r}: {e}") from e
+        else:
+            exclude_pattern = None
 
         ret = []
         for term in terms: