diff --git a/.gitignore b/.gitignore
index d64b2e68c53ed65c8b3fab9bbd42e7b63def5adf..8c867ec17e344ac921c46edbe43f2e1c47c5b919 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,9 @@
 .ExternalData_*
 .ExternalData/config
 
+# Do not commit baseline image files.
+**/Testing/Data/Baseline/*.png
+
 # Exclude compiled Python objects.
 *.pyc
 *.pyo