High Quality Content by WIKIPEDIA articles! Season one of Grey`s Anatomy, an American medical drama television series developed by Shonda Rhimes, began airing on March 27, 2005 on ABC. The season concluded on May 22, 2005, after 9 episodes aired. Season one regular cast members include Ellen Pompeo, Sandra Oh, Katherine Heigl, Justin Chambers, T.R. Knight, Chandra Wilson, James Pickens, Jr., Isaiah Washington and Patrick Dempsey.