diff --git a/doc/sphinx/_static/powered_by_NumFOCUS.png b/doc/sphinx/_static/powered_by_NumFOCUS.png
new file mode 100644
index 000000000..33d420fbf
Binary files /dev/null and b/doc/sphinx/_static/powered_by_NumFOCUS.png differ
diff --git a/doc/sphinx/_templates/numfocus.html b/doc/sphinx/_templates/numfocus.html
new file mode 100644
index 000000000..f1db0f138
--- /dev/null
+++ b/doc/sphinx/_templates/numfocus.html
@@ -0,0 +1,5 @@
+<div id="numfocus">
+<h3>Donate to Cantera</h3>
+<a href="https://www.flipcause.com/secure/cause_pdetails/Mjk3MjU=">
+<img src="{{pathto("_static/powered_by_NumFOCUS.png", 1) }}" border="0" alt="NumFOCUS"/></a>
+</div>
diff --git a/doc/sphinx/conf.py b/doc/sphinx/conf.py
index f00a4f294..e6b36cd5e 100644
--- a/doc/sphinx/conf.py
+++ b/doc/sphinx/conf.py
@@ -130,6 +130,7 @@ pygments_style = 'sphinx'
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
 html_theme = 'cttheme'
+html_sidebars = {'**': ['localtoc.html', 'relations.html', 'sourcelink.html', 'searchbox.html', 'numfocus.html']}
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the