diff --git a/internal/markdown/markdown.go b/internal/markdown/markdown.go
index b7fe25e..1d7e9e6 100644
--- a/internal/markdown/markdown.go
+++ b/internal/markdown/markdown.go
@@ -362,6 +362,7 @@ func init() {
 	md = goldmark.New(
 		goldmark.WithExtensions(
 			extension.GFM,
+			extension.Footnote,
 			highlighting.NewHighlighting(
 				highlighting.WithStyle("github"),
 			),
@@ -377,6 +378,15 @@ func init() {
 	// Allow task list checkboxes generated by goldmark GFM
 	policy.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
 	policy.AllowAttrs("checked", "disabled").OnElements("input")
+	// Footnote support
+	policy.AllowElements("sup", "hr")
+	policy.AllowAttrs("id").Matching(regexp.MustCompile(`^fnref\d*:\d+$`)).OnElements("sup")
+	policy.AllowAttrs("id").Matching(regexp.MustCompile(`^fn:\d+$`)).OnElements("li")
+	policy.AllowAttrs("class").Matching(regexp.MustCompile(`^footnote-ref$`)).OnElements("a")
+	policy.AllowAttrs("class").Matching(regexp.MustCompile(`^footnote-backref$`)).OnElements("a")
+	policy.AllowAttrs("class").Matching(regexp.MustCompile(`^footnotes$`)).OnElements("div")
+	policy.AllowAttrs("role").Matching(regexp.MustCompile(`^doc-(noteref|backlink|endnotes)$`)).OnElements("a", "div")
+	policy.AllowAttrs("href").Matching(regexp.MustCompile(`^#fn(ref\d*)?:\d+$`)).OnElements("a")
 }
 
 // ExtractMentions returns unique @usernames found in the raw markdown text.
diff --git a/web/static/css/input.css b/web/static/css/input.css
index 0c44115..fd393cc 100644
--- a/web/static/css/input.css
+++ b/web/static/css/input.css
@@ -34,6 +34,22 @@ pre.mermaid {
     overflow-x: auto;
 }
 
+/* Footnote styling */
+.prose .footnotes {
+    border-top: 1px solid var(--color-gray-300);
+    margin-top: 1.5rem;
+    padding-top: 1rem;
+    font-size: 0.875rem;
+    color: var(--color-gray-600);
+}
+.prose sup a {
+    color: var(--color-blue-600);
+    text-decoration: none;
+}
+.prose sup a:hover {
+    text-decoration: underline;
+}
+
 /* Task list checkbox styling */
 .prose input[type="checkbox"] {
     margin-right: 0.375rem;