XX/XY is a 2002 American romantic drama film written and directed by Austin Chick and starring Mark Ruffalo, Kathleen Robertson, and Maya Stange. The title refers to the different chromosome pairings present in men and women. XX/XY premiered in competition at the 2002 Sundance Film Festival. Although the funding for the film came from the US, the film was produced by British company Natural Nylon.