"Don't Let Him Know" is a song by Canadian rock band Prism, written by Jim Vallance and Bryan Adams.

It was the first single from the band's fifth studio album, Small Change (1981).

"Don't Let Him Know" was Prism's biggest US hit, peaking at No.

The song and footage of the band performing were later used in a commercial for Craig car stereos.

Prism In 2009, Prism re-recorded "Don't Let Him Know" with Al Harlow on lead vocals.