The third season of The Hills, an American reality television series, consists of 28 episodes and was broadcast on MTV. The first portion aired from August 13, 2007, until December 10, 2007, while the second portion aired from March 24, 2008, until May 12, 2008. It was primarily filmed in Los Angeles, California, with additional footage in Crested Butte, Colorado; Las Vegas, Nevada; and Paris, France. The executive producer was Liz Gateley.

The Hills focuses on the lives of Lauren Conrad, Audrina Patridge, Whitney Port, and Heidi Montag. During the season, Conrad ended her friendship with Montag after suspecting that she and her boyfriend Spencer Pratt fabricated rumors of a sex tape involving herself and ex-boyfriend Jason Wahler. The ensuing feud between the three became a central focus of the series, and was carried through each subsequent season. Meanwhile, Patridge resumed a relationship with her on-again/off-again boyfriend Justin Brescia.