The Parent Trap (1998)

Already a family classic, Hallie and Annie share a summer camp and discover they are twin sisters. Hallie lives in California with her dad and Annie lives in London with her mom. The two, cunning and resourceful, organize a plan to impersonate their identities. They want to get their parents back together, but they don't know that their father intends to marry his publicist, Meredith Blake.