diff --git a/docusaurus.config.js b/docusaurus.config.js
index 9c83c33b..dd2e8a7c 100644
--- a/docusaurus.config.js
+++ b/docusaurus.config.js
@@ -56,14 +56,6 @@ const config = {
   themeConfig:
     /** @type {import('@docusaurus/preset-classic').ThemeConfig} */
     ({
-      announcementBar: {
-        id: "tskaigi2026",
-        content:
-          '📣 <a target="_blank" rel="noopener noreferrer" href="https://2026.tskaigi.org/">TSKaigi 2026</a> — 2026年5月22日-23日 ベルサール羽田空港にて開催！',
-        backgroundColor: "#0D47A1",
-        textColor: "#FFFFFF",
-        isCloseable: true,
-      },
       image: "img/docusaurus-social-card.jpg",
       navbar: {
         title: "サバイバルTypeScript",
diff --git a/src/theme/TOC/index.tsx b/src/theme/TOC/index.tsx
index 8629ff04..51f10cb9 100644
--- a/src/theme/TOC/index.tsx
+++ b/src/theme/TOC/index.tsx
@@ -10,18 +10,6 @@ const LINK_ACTIVE_CLASS_NAME = "table-of-contents__link--active";
 export default function TOC({ className, ...props }: Props): JSX.Element {
   return (
     <div className={clsx(styles.tableOfContents, "thin-scrollbar", className)}>
-      <a
-        href="https://2026.tskaigi.org/"
-        target="_blank"
-        rel="noopener noreferrer"
-        className={styles.tocBanner}
-      >
-        <img
-          src="/img/sponsors/tskaigi2026-banner.png"
-          alt="TSKaigi 2026 — 2026年5月22日-23日 ベルサール羽田空港にて開催"
-          className={styles.tocBannerImage}
-        />
-      </a>
       <TOCItems
         {...props}
         linkClassName={LINK_CLASS_NAME}
diff --git a/static/img/sponsors/tskaigi2026-banner.png b/static/img/sponsors/tskaigi2026-banner.png
deleted file mode 100644
index 455b24f0..00000000
Binary files a/static/img/sponsors/tskaigi2026-banner.png and /dev/null differ