Grey's Anatomy is an American television medical drama that premiered on the American Broadcasting Company (ABC) as a mid-season replacement on March 27, 2005. The series has aired nine seasons, and focuses on the fictional lives of surgical interns and residents as they gradually evolve into seasoned doctors, while trying to maintain personal lives. The show's premise originated with Shonda Rhimes, who serves as an executive producer, along with Betsy Beers, Mark Gordon, Krista Vernoff, Rob Corn, Mark Wilding, and Allan Heinberg. The series was created to be racially diverse, utilizing a color-blind casting technique. It is primarily filmed in Los Angeles, California.

The series' protagonist is Dr. Meredith Grey (Ellen Pompeo), who originally is accepted into the residency program at the fictional Seattle Grace Hospital. Meredith is assigned to work under Dr. Miranda Bailey (Chandra Wilson), along with Dr. Cristina Yang (Sandra Oh), Dr. George O'Malley (T. R. Knight), Dr. Izzie Stevens (Katherine Heigl), and Dr. Alex Karev (Justin Chambers). Following O'Malley's death and Stevens' departure, the hospital's merger with Mercy West brings in Dr. Jackson Avery (Jesse Williams) and Dr. April Kepner (Sarah Drew), in the sixth season.
The surgical wing is primarily supervised by Dr. Richard Webber (James Pickens, Jr.), who is eventually replaced by Dr. Derek Shepherd (Patrick Dempsey), and later, Dr. Owen Hunt (Kevin McKidd). Dr. Derek Shepherd (Patrick Dempsey) is the chief of neurology, Dr. Miranda Bailey (Chandra Wilson) is the chief of general surgery, Dr. Arizona Robbins (Jessica Capshaw) is chief of pediatrics, Owen Hunt (Kevin McKidd) is chief of trauma, Dr. Mark Sloan (Eric Dane) is the chief of plastic surgery, and the chief of cardiology has been three different people throughout the show: Dr. Preston Burke (Isaiah Washington), Dr. Erica Hahn (Brooke Smith), and Dr. Teddy Altman (Kim Raver).

Dr. Preston Burke (Isaiah Washington) departs at the conclusion of the third season, after a failed relationship with Dr. Cristina Yang, and is replaced by Dr. Erica Hahn (Brooke Smith), who leaves the show during the fifth season, and later Dr. Teddy Altman (Kim Raver), who departs at the end of the eighth season. Introduced in the second season is Dr. Addison Montgomery (Kate Walsh), who leaves the show at the end of the third season, in order to launch her own spin-off medical drama Private Practice. Dr. Callie Torres (Sara Ramirez) and Dr. Mark Sloan (Eric Dane) also enter the show in the second season, while the latter dies in the premiere of the ninth season. Meredith's half-sister, Dr. Lexie Grey (Chyler Leigh), appears from season three and dies at the end of season eight. Dr. Arizona Robbins (Jessica Capshaw) is given series regular status at the beginning of the sixth season.

Grey's Anatomy is the highest-rated drama in the key 18–49 demographic. While the ratings have fallen over the past few seasons, it was once among the overall top-ten rated shows in the United States. Grey's Anatomy has been well received by critics. Considered an impact on culture, the series has received numerous awards, and has also been included in various critics' top ten lists. The show has produced several specials, as well as distributed all seasons to DVD, and released a collection of merchandise. In 2012, Grey's Anatomy was named the fifth-highest revenue earning show, in terms of advertising per half-hour. The series was renewed for a tenth season on May 10, 2013. Season 10 is set to premiere on September 26, 2013. The season will be split into two parts, with 12 episodes in each part. The second part of season 10 will premiere on February 27, 2014.