Guess Who's Coming to Dinner (Grey's Anatomy)

"Guess Who's Coming to Dinner" is the fifth episode of the twelfth season of the American television medical drama Grey's Anatomy, and the 250th episode overall. Written by Mark Driscoll and directed by executive producer Debbie Allen, it aired on the American Broadcasting Company (ABC) in the United States on October 22, 2015.

The episode centers around the dinner party hosted by Meredith Grey (Ellen Pompeo), Amelia Shepherd (Caterina Scorsone) and Maggie Pierce (Kelly McCreary). Tensions arise when Callie Torres' (Sara Ramirez) new girlfriend Penelope "Penny" Blake (Samantha Sloyan), is introduced, and it is revealed that Blake was one of Derek Shepherd's (Patrick Dempsey) doctors when he died. The episode also follows Arizona Robbins (Jessica Capshaw) as she attempts to adjust to Callie's new relationship, April Kepner (Sarah Drew) as she distracts herself from her ongoing issues with her estranged husband Jackson Avery (Jesse Williams), and a heated argument between Jo Wilson (Camilla Luddington) and Stephanie Edwards (Jerrika Hinton).

On its initial airing, "Guess Who's Coming to Dinner" was watched by a total of 8.96 million viewers and scored a 2.4/8 in the key 18–49 demographic in the Nielsen ratings, ranking at #1 for the time slot. It received universal acclaim, with numerous critics calling it one of the best episodes of the series in recent years, and Pompeo and Scorsone's performances received widespread praise.