diff --git a/docs/api_reference/_static/css/custom.css b/docs/api_reference/_static/css/custom.css
index cf06028c5e5..8fc6a4d40d8 100644
--- a/docs/api_reference/_static/css/custom.css
+++ b/docs/api_reference/_static/css/custom.css
@@ -394,3 +394,21 @@ p {
   font-size: 0.9rem;
   margin-bottom: 0.5rem;
 }
+
+/* Deprecation announcement banner styling */
+.bd-header-announcement {
+  background-color: #790000 !important;
+  color: white !important;
+  font-weight: 600;
+  padding: 0.75rem 1rem;
+  text-align: center;
+}
+
+.bd-header-announcement a {
+  color: white !important;
+  text-decoration: underline !important;
+}
+
+.bd-header-announcement a:hover {
+  color: #f0f0f0 !important;
+}
diff --git a/docs/api_reference/conf.py b/docs/api_reference/conf.py
index cac42d53feb..12fc8ea9122 100644
--- a/docs/api_reference/conf.py
+++ b/docs/api_reference/conf.py
@@ -218,7 +218,7 @@ html_theme_options = {
     #     # Use :html_theme.sidebar_secondary.remove: for file-wide removal
     #     "secondary_sidebar_items": {"**": ["page-toc", "sourcelink"]},
     #     "show_version_warning_banner": True,
-    #     "announcement": None,
+    "announcement": "⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank' style='color: white; text-decoration: underline;'>Visit the new v1.0 docs</a> and new <a href='https://reference.langchain.com/python' target='_blank' style='color: white; text-decoration: underline;'>reference docs</a>",
     "icon_links": [
         {
             # Label for this link
diff --git a/docs/api_reference/create_api_rst.py b/docs/api_reference/create_api_rst.py
index 14e65ff1027..eef94739305 100644
--- a/docs/api_reference/create_api_rst.py
+++ b/docs/api_reference/create_api_rst.py
@@ -618,11 +618,14 @@ def _build_index(dirs: List[str]) -> None:
 Welcome to the LangChain v0.3 Python API reference. This is a reference for all
 `langchain-x` packages.
 
+```{danger}
 These pages refer to the the v0.3 versions of LangChain packages and integrations. To
 visit the documentation for the latest versions of LangChain, visit [https://docs.langchain.com](https://docs.langchain.com)
 and [https://reference.langchain.com/python/](https://reference.langchain.com/python/) (for references.)
 
 For the legacy API reference (<v0.3) hosted on ReadTheDocs see [https://api.python.langchain.com/](https://api.python.langchain.com/).
+```
+
 """
 
     if main_:
diff --git a/docs/docs/concepts/index.mdx b/docs/docs/concepts/index.mdx
index eeff6fe2f33..c7e7c6173af 100644
--- a/docs/docs/concepts/index.mdx
+++ b/docs/docs/concepts/index.mdx
@@ -1,3 +1,7 @@
+:::danger
+⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the new v1.0 docs</a>
+:::
+
 # Conceptual guide
 
 This guide provides explanations of the key concepts behind the LangChain framework and AI applications more broadly.
diff --git a/docs/docs/how_to/index.mdx b/docs/docs/how_to/index.mdx
index 5a78a7fddd6..4f906c4f5e5 100644
--- a/docs/docs/how_to/index.mdx
+++ b/docs/docs/how_to/index.mdx
@@ -3,6 +3,10 @@ sidebar_position: 0
 sidebar_class_name: hidden
 ---
 
+:::danger
+⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the new v1.0 docs</a>
+:::
+
 # How-to guides
 
 Here you’ll find answers to "How do I….?" types of questions.
diff --git a/docs/docs/introduction.mdx b/docs/docs/introduction.mdx
index de01d3d4401..418f692341f 100644
--- a/docs/docs/introduction.mdx
+++ b/docs/docs/introduction.mdx
@@ -3,6 +3,10 @@ sidebar_position: 0
 sidebar_class_name: hidden
 ---
 
+:::danger
+⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the new v1.0 docs</a>
+:::
+
 # Introduction
 
 **LangChain** is a framework for developing applications powered by large language models (LLMs).
diff --git a/docs/docs/tutorials/index.mdx b/docs/docs/tutorials/index.mdx
index c960903c358..16fae330675 100644
--- a/docs/docs/tutorials/index.mdx
+++ b/docs/docs/tutorials/index.mdx
@@ -2,6 +2,11 @@
 sidebar_position: 0
 sidebar_class_name: hidden
 ---
+
+:::danger
+⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the new v1.0 docs</a>
+:::
+
 # Tutorials
 
 New to LangChain or LLM app development in general? Read this material to quickly get up and running building your first applications.
diff --git a/docs/docusaurus.config.js b/docs/docusaurus.config.js
index e6740c21e1e..508dcb575c8 100644
--- a/docs/docusaurus.config.js
+++ b/docs/docusaurus.config.js
@@ -142,8 +142,8 @@ const config = {
         respectPrefersColorScheme: true,
       },
       announcementBar: {
-        content: "These docs will be deprecated and no longer maintained with the release of LangChain v1.0 in October 2025. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the v1.0 alpha docs</a>",
-        backgroundColor: "#FFAE42",
+        content: "⚠️ THESE DOCS ARE OUTDATED. <a href='https://docs.langchain.com/oss/python/langchain/overview' target='_blank'>Visit the new v1.0 docs</a>",
+        backgroundColor: "#790000ff",
       },
       prism: {
         theme: {