Mutt and Jeff is a long-running and widely popular American newspaper comic strip created by cartoonist Bud Fisher in 1907 about "two mismatched tinhorns". It is commonly regarded as the first daily comic strip. The concept of a newspaper strip featuring recurring characters in multiple panels on a six-day-a-week schedule had previously been pioneered through the short-lived A. Piker Clerk by Clare Briggs, but it was Mutt and Jeff as the first successful daily comic strip that staked out the direction of the future trend.

Harry Conway "Bud" Fisher was an American cartoonist who created Mutt and Jeff, the first successful daily comic strip in the United States.