diff --git a/ulii/settings.py b/ulii/settings.py
index d0bdc5883..49eab793b 100644
--- a/ulii/settings.py
+++ b/ulii/settings.py
@@ -35,3 +35,10 @@
     "center-arbitration-dispute-resolution-uganda": "UGCADER",
     "tax-appeals-tribunal-uganda": "UGTAT",
 }
+
+
+if not DEBUG:  # noqa
+    # ULII media files are stored on S3 and served via a Cloudflare CDN (via copying to R2).
+    # We can therefore set long-lived cache headers and serve them from a custom domain.
+    AWS_S3_OBJECT_PARAMETERS = {"CacheControl": f"max-age={86400*5}"}
+    AWS_S3_CUSTOM_DOMAIN = "media.ulii.org"