"Didn't We Almost Have It All?" is the twenty-fifth episode and the season finale of the third season of the American television medical drama Grey's Anatomy, and is the 61st episode overall. It was written by Tony Phelan and Joan Rater and directed by Rob Corn. The episode originally aired on the American Broadcasting Company (ABC) in the United States on May 17, 2007. The episode runs for 53:05 minutes, making it the longest episode of the series, excluding 2-part episodes. The title of the episode refers to the song "Didn't We Almost Have It All", by American singer Whitney Houston.

The third season of the American television medical drama Grey's Anatomy, commenced airing on the American Broadcasting Company (ABC) on September 21, 2006, and concluded on May 17, 2007. The season was produced by Touchstone Television, in association with Shondaland Production Company and The Mark Gordon Company, the showrunner being Shonda Rhimes. Actors Ellen Pompeo, Sandra Oh, Katherine Heigl, Justin Chambers and T. R. Knight reprised their roles as surgical interns Meredith Grey, Cristina Yang, Izzie Stevens, Alex Karev and George O'Malley, respectively, continuing their expansive storylines as focal points throughout the season. Previous main cast members Chandra Wilson, James Pickens, Jr., Kate Walsh, Isaiah Washington, and Patrick Dempsey also returned, while previous guest-stars Sara Ramirez and Eric Dane were promoted to series-regulars, following the extension of their contracts.