IF is a American live-action/animated fantasy comedy film written, directed, and produced by John Krasinski. The film features an ensemble cast that includes Ryan Reynolds, Krasinski, Cailey Fleming, Fiona Shaw, Alan Kim, and Liza Colón-Zayas, along with the voices of Phoebe Waller-Bridge, Louis Gossett Jr., and Steve Carell. Its plot follows a young girl and her neighbor who find themselves able to see imaginary friends.