The fourth season of the American television series Bones premiered on September 3, 2008, with a two-hour episode, and concluded on May 14, 2009, on Fox.

[1] The season premieres with its first two-part episode, "The Yanks in the U.K." which was filmed on-location in the United Kingdom.

After Booth is rescued, the team discovers the true identity of The Grave Digger.

While the Blu-ray release, and the region 2 and 4 versions include all 26 episodes of the season.

Special features include two featurettes—"Androgyny: Playing Haru Tanaka" and "Squints in Training"; three extended episodes—"The Perfect Pieces in the Purple Pond", "The Doctor in the Den" and "The Girl in the Mask".