CW 21 may refer to the following television stations in the U.S. affiliated with The CW:

Current affiliates WBRL-CD in Baton Rouge, Louisiana (O&O) WBAE in Alpena, Michigan (cable-only)

Former affiliates WTTO in Birmingham, Alabama (2006–2026) WWMB in Florence, South Carolina (2006–2021), now on WPDE-DT2