RatDog is an American rock band. The group began in 1995 as a side project for Grateful Dead guitarist and singer Bob Weir. After the Dead disbanded later that year, RatDog became Weir's primary band. They performed some Grateful Dead songs, a mixture of covers (including Bob Dylan and Chuck Berry tunes), and some originals. They released two albums – Evening Moods (2000) and Live at Roseland (2001). RatDog has not toured since July 2014.

The lineup of RatDog evolved over time. Musicians who were members of the band at different times include Rob Wasserman and Robin Sylvester on bass, Jay Lane on drums, Matthew Kelly, Mark Karan, and Steve Kimock on guitar, and Vince Welnick, Johnny Johnson and Jeff Chimenti on keyboards.