James Burgon Valentine (born October 5, 1978) is an American musician who is the lead guitarist and backing vocalist for the pop band Maroon 5.

In 2000, Happy Dog changed its name to Square and he moved to Los Angeles from Anaheim, California, where he taught private guitar lessons out of his home.

Valentine displayed a picture from one Reel Big Fish show he played during Maroon 5's appearance on MTV Cribs.

Eventually the members of Square and Kara's Flowers became friends and when Adam Levine, Jesse Carmichael, Mickey Madden and Ryan Dusick began looking for another guitarist, Valentine was approached.

Personal tensions in Square helped the decision to join the band and shortly afterward, Kara's Flowers became Maroon 5.

Valentine also played guitar on Jenny Lewis' 2006 solo album, Rabbit Fur Coat with The Watson Twins and has appeared in her music video for the first single, "Rise Up with Fists!!".

Phases (originally called JJAMZ) is a band composed of James Valentine (Maroon 5), Jason Boesel (Rilo Kiley/Conor Oberst), Alex Greenwald (Phantom Planet), Michael Runion (solo), and Z Berg (The Like).