diff --git a/CHANGELOG.md b/CHANGELOG.md
index 10c58b1e4bd..d36c200f695 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## [4.14.3] - 2021-01-12
 
 ### Fixed
+- Plotly.js cdn url will now be versioned by default for: 
+  `include_plotlyjs='cdn'` a new `include_plotlyjs='cdn-latest'` option 
+  has the original behaviour. Prevents likelihood of htmls generated with older 
+  `plotly.js` versions breaking with version bumps. 
+  [2961](https://github.com/plotly/plotly.py/pull/2961)
 
 - `px.timeline()` now allows `hover_data` formatting of start and end times [3018](https://github.com/plotly/plotly.py/pull/3018)
 - Small change to packaging of `plotlywidget` extension for JupyterLab 3 [3021](https://github.com/plotly/plotly.py/pull/3021)
diff --git a/packages/python/plotly/plotly/io/_base_renderers.py b/packages/python/plotly/plotly/io/_base_renderers.py
index f5aec7e61cd..8eb947efe8d 100644
--- a/packages/python/plotly/plotly/io/_base_renderers.py
+++ b/packages/python/plotly/plotly/io/_base_renderers.py
@@ -7,9 +7,10 @@
 from os.path import isdir
 
 import six
-from plotly.io import to_json, to_image, write_image, write_html
 from plotly import utils, optional_imports
+from plotly.io import to_json, to_image, write_image, write_html
 from plotly.io._orca import ensure_server
+from plotly.io._utils import plotly_cdn_url
 from plotly.offline.offline import _get_jconfig, get_plotlyjs
 from plotly.tools import return_figure_from_figure_or_data
 
@@ -289,7 +290,7 @@ def activate(self):
         require.undef("plotly");
         requirejs.config({{
             paths: {{
-                'plotly': ['https://cdn.plot.ly/plotly-latest.min']
+                'plotly': ['{plotly_cdn}']
             }}
         }});
         require(['plotly'], function(Plotly) {{
@@ -298,7 +299,9 @@ def activate(self):
         }}
         </script>
         """.format(
-                    win_config=_window_plotly_config, mathjax_config=_mathjax_config
+                    win_config=_window_plotly_config,
+                    mathjax_config=_mathjax_config,
+                    plotly_cdn=plotly_cdn_url().rstrip(".js"),
                 )
 
             else:
diff --git a/packages/python/plotly/plotly/io/_html.py b/packages/python/plotly/plotly/io/_html.py
index 550a96f1d86..b279d91fccc 100644
--- a/packages/python/plotly/plotly/io/_html.py
+++ b/packages/python/plotly/plotly/io/_html.py
@@ -6,7 +6,7 @@
 import six
 
 from _plotly_utils.optional_imports import get_module
-from plotly.io._utils import validate_coerce_fig_to_dict
+from plotly.io._utils import validate_coerce_fig_to_dict, plotly_cdn_url
 from plotly.offline.offline import _get_jconfig, get_plotlyjs
 from plotly import utils
 
@@ -61,10 +61,16 @@ def to_html(
         fully self-contained and can be used offline.
 
         If 'cdn', a script tag that references the plotly.js CDN is included
-        in the output. HTML files generated with this option are about 3MB
-        smaller than those generated with include_plotlyjs=True, but they
-        require an active internet connection in order to load the plotly.js
-        library.
+        in the output. The url used is versioned to match the bundled plotly.js.
+        HTML files generated with this option are about 3MB smaller than those
+        generated with include_plotlyjs=True, but they require an active
+        internet connection in order to load the plotly.js library.
+
+        If 'cdn-latest', a script tag that always references the latest plotly.js
+        CDN is included in the output.
+        HTML files generated with this option are about 3MB smaller than those
+        generated with include_plotlyjs=True, but they require an active
+        internet connection in order to load the plotly.js library.
 
         If 'directory', a script tag is included that references an external
         plotly.min.js bundle that is assumed to reside in the same
@@ -266,12 +272,15 @@ def to_html(
         require_start = 'require(["plotly"], function(Plotly) {'
         require_end = "});"
 
-    elif include_plotlyjs == "cdn":
+    elif include_plotlyjs == "cdn" or include_plotlyjs == "cdn-latest":
+        cdn_url = plotly_cdn_url()
+        if include_plotlyjs == "cdn-latest":
+            cdn_url = plotly_cdn_url(cdn_ver="latest")
         load_plotlyjs = """\
         {win_config}
-        <script src="https://cdn.plot.ly/plotly-latest.min.js"></script>\
+        <script src="{cdn_url}"></script>\
     """.format(
-            win_config=_window_plotly_config
+            win_config=_window_plotly_config, cdn_url=cdn_url
         )
 
     elif include_plotlyjs == "directory":
@@ -417,10 +426,16 @@ def write_html(
         fully self-contained and can be used offline.
 
         If 'cdn', a script tag that references the plotly.js CDN is included
-        in the output. HTML files generated with this option are about 3MB
-        smaller than those generated with include_plotlyjs=True, but they
-        require an active internet connection in order to load the plotly.js
-        library.
+        in the output. The url used is versioned to match the bundled plotly.js.
+        HTML files generated with this option are about 3MB smaller than those
+        generated with include_plotlyjs=True, but they require an active
+        internet connection in order to load the plotly.js library.
+
+        If 'cdn-latest', a script tag that always references the latest plotly.js
+        CDN is included in the output.
+        HTML files generated with this option are about 3MB smaller than those
+        generated with include_plotlyjs=True, but they require an active
+        internet connection in order to load the plotly.js library.
 
         If 'directory', a script tag is included that references an external
         plotly.min.js bundle that is assumed to reside in the same
diff --git a/packages/python/plotly/plotly/io/_utils.py b/packages/python/plotly/plotly/io/_utils.py
index 289ffa2c1a7..5bc03271148 100644
--- a/packages/python/plotly/plotly/io/_utils.py
+++ b/packages/python/plotly/plotly/io/_utils.py
@@ -2,6 +2,7 @@
 
 import plotly
 import plotly.graph_objs as go
+from plotly.offline import get_plotlyjs_version
 
 
 def validate_coerce_fig_to_dict(fig, validate):
@@ -42,3 +43,8 @@ def validate_coerce_output_type(output_type):
     Must be one of: 'Figure', 'FigureWidget'"""
         )
     return cls
+
+
+def plotly_cdn_url(cdn_ver=get_plotlyjs_version()):
+    """Return a valid plotly CDN url."""
+    return "https://cdn.plot.ly/plotly-{cdn_ver}.min.js".format(cdn_ver=cdn_ver,)
diff --git a/packages/python/plotly/plotly/tests/test_core/test_offline/test_offline.py b/packages/python/plotly/plotly/tests/test_core/test_offline/test_offline.py
index 249827a6744..0b5368113de 100644
--- a/packages/python/plotly/plotly/tests/test_core/test_offline/test_offline.py
+++ b/packages/python/plotly/plotly/tests/test_core/test_offline/test_offline.py
@@ -12,6 +12,8 @@
 
 import plotly
 import plotly.io as pio
+from plotly.io._utils import plotly_cdn_url
+
 import json
 
 packages_root = os.path.dirname(
@@ -39,7 +41,7 @@
 <script type="text/javascript">\
 window.PlotlyConfig = {MathJaxConfig: 'local'};</script>"""
 
-cdn_script = '<script src="https://cdn.plot.ly/plotly-latest.min.js">' "</script>"
+cdn_script = '<script src="{cdn_url}"></script>'.format(cdn_url=plotly_cdn_url())
 
 directory_script = '<script src="plotly.min.js"></script>'
 
diff --git a/packages/python/plotly/plotly/tests/test_io/test_html.py b/packages/python/plotly/plotly/tests/test_io/test_html.py
new file mode 100644
index 00000000000..026677c0d58
--- /dev/null
+++ b/packages/python/plotly/plotly/tests/test_io/test_html.py
@@ -0,0 +1,52 @@
+import sys
+
+import pytest
+import numpy as np
+
+
+import plotly.graph_objs as go
+import plotly.io as pio
+from plotly.io._utils import plotly_cdn_url
+
+
+if sys.version_info >= (3, 3):
+    import unittest.mock as mock
+    from unittest.mock import MagicMock
+else:
+    import mock
+    from mock import MagicMock
+
+# fixtures
+# --------
+@pytest.fixture
+def fig1(request):
+    return go.Figure(
+        data=[
+            {
+                "type": "scatter",
+                "y": np.array([2, 1, 3, 2, 4, 2]),
+                "marker": {"color": "green"},
+            }
+        ],
+        layout={"title": {"text": "Figure title"}},
+    )
+
+
+# HTML
+# ----
+def assert_latest_cdn_connected(html):
+    assert plotly_cdn_url(cdn_ver="latest") in html
+
+
+def assert_locked_version_cdn_connected(html):
+    assert plotly_cdn_url() in html
+
+
+def test_latest_cdn_included(fig1):
+    html_str = pio.to_html(fig1, include_plotlyjs="cdn-latest")
+    assert_latest_cdn_connected(html_str)
+
+
+def test_versioned_cdn_included(fig1):
+    html_str = pio.to_html(fig1, include_plotlyjs="cdn")
+    assert_locked_version_cdn_connected(html_str)
diff --git a/packages/python/plotly/plotly/tests/test_io/test_renderers.py b/packages/python/plotly/plotly/tests/test_io/test_renderers.py
index 27e1e6ea6de..ee11c412fb7 100644
--- a/packages/python/plotly/plotly/tests/test_io/test_renderers.py
+++ b/packages/python/plotly/plotly/tests/test_io/test_renderers.py
@@ -11,6 +11,7 @@
 import plotly.graph_objs as go
 import plotly.io as pio
 from plotly.offline import get_plotlyjs
+from plotly.io._utils import plotly_cdn_url
 
 if sys.version_info >= (3, 3):
     import unittest.mock as mock
@@ -134,8 +135,8 @@ def assert_not_full_html(html):
     assert not html.startswith("<html")
 
 
-def assert_connected(html):
-    assert "https://cdn.plot.ly/plotly-latest.min" in html
+def assert_html_renderer_connected(html):
+    assert plotly_cdn_url().rstrip(".js") in html
 
 
 def assert_offline(html):
@@ -166,7 +167,7 @@ def test_colab_renderer_show(fig1):
     # Check html contents
     html = mock_arg1["text/html"]
     assert_full_html(html)
-    assert_connected(html)
+    assert_html_renderer_connected(html)
     assert_not_requirejs(html)
 
     # check kwargs
@@ -195,7 +196,7 @@ def test_notebook_connected_show(fig1, name, connected):
     # Check init display contents
     bundle_display_html = mock_arg1_html
     if connected:
-        assert_connected(bundle_display_html)
+        assert_html_renderer_connected(bundle_display_html)
     else:
         assert_offline(bundle_display_html)
 
@@ -306,7 +307,7 @@ def test_repr_html(renderer):
     template = (
         '<div>                        <script type="text/javascript">'
         "window.PlotlyConfig = {MathJaxConfig: 'local'};</script>\n        "
-        '<script src="https://cdn.plot.ly/plotly-latest.min.js"></script>                '
+        '<script src="' + plotly_cdn_url() + '"></script>                '
         '<div id="cd462b94-79ce-42a2-887f-2650a761a144" class="plotly-graph-div" '
         'style="height:100%; width:100%;"></div>            <script type="text/javascript">'
         "                                    window.PLOTLYENV=window.PLOTLYENV || {};"