Bullock, 40, and James, 35, exchanged vows Saturday in front of several hundred guests at the Folded Hills Ranch in Santa Ynez Valley's wine country.
Guests included actor William Shatner, actresses Jamie Lee Curtis and Regina King, and Metallica lead singer James Hetfield, according to "Entertainment Tonight" and Us Weekly magazine.
Many in Hollywood have been surprised at the pairing of the tattooed bad boy James and the on-screen good girl Bullock. They met in 2003.
It's the first marriage for "Miss Congeniality" star Bullock, who had been engaged to actor Tate Donovan. She recently played the wife of a district attorney in the film "Crash."
James, who previously married twice and has three children, appears on The Discovery Channel's "Monster Garage."