Geraldine Margaret Agnew-Somerville is an Irish actress. She is known for portraying Lady Stockbridge in Gosford Park (2001) and Lily Potter in the Harry Potter film series (2001-2011). Her other roles have included My Week with Marilyn (2011), Grace of Monaco (2014) and Kids in Love (2016). In 1995, Somerville was nominated for a BAFTA Award for playing Jane Penhaligon in the television series Cracker from 1993 to 1995.