The River Pang is a small chalk stream river in the west of the English county of Berkshire, and a tributary of the River Thames. It runs for approximately 23 kilometres (14 mi) from its source near the village of Compton to its confluence with the Thames in the village of Pangbourne.

Chalk streams are rivers that rise from springs in landscapes with chalk bedrock. Since chalk is permeable, water percolates easily through the ground to the water table and chalk streams therefore receive little surface runoff. As a result, the water in the streams contains little organic matter and sediment and is generally very clear.