A composition for an optical film, comprising: a liquid crystal, and a polysiloxane comprising a structural unit represented by Chemical Formula 1A and a structural unit represented by Chemical Formula 1B: wherein, in Chemical Formulae 1A and 1B, R 1 and R 2 are independently selected from hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, and a combination thereof, L 1 and L 2 are independently selected from a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, and a combination thereof, X is selected from a substituted or unsubstituted C6 to C30 aryl group and a substituted or unsubstituted C3 to C30 heteroaryl group, and Y is selected from a substituted or unsubstituted acryloxy group, a substituted or unsubstituted methacryloxy group, a substituted or unsubstituted acryloyl group, a substituted or unsubstituted methacryloyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C2 to C30 alkenyloxy group, a substituted or unsubstituted C2 to C30 alkynyl group, and a substituted or unsubstituted C2 to C30 alkynyloxy group. a liquid crystal, and a polysiloxane comprising a structural unit represented by Chemical Formula 1A and a structural unit represented by Chemical Formula 1B: wherein, in Chemical Formulae 1A and 1B, R 1 and R 2 are independently selected from hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, and a combination thereof, L 1 and L 2 are independently selected from a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, and a combination thereof, X is selected from a substituted or unsubstituted C6 to C30 aryl group and a substituted or unsubstituted C3 to C30 heteroaryl group, and Y is selected from a substituted or unsubstituted acryloxy group, a substituted or unsubstituted methacryloxy group, a substituted or unsubstituted acryloyl group, a substituted or unsubstituted methacryloyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C2 to C30 alkenyloxy group, a substituted or unsubstituted C2 to C30 alkynyl group, and a substituted or unsubstituted C2 to C30 alkynyloxy group. R 1 and R 2 are independently selected from hydrogen, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, and a combination thereof, L 1 and L 2 are independently selected from a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, and a combination thereof, X is selected from a substituted or unsubstituted C6 to C30 aryl group and a substituted or unsubstituted C3 to C30 heteroaryl group, and Y is selected from a substituted or unsubstituted acryloxy group, a substituted or unsubstituted methacryloxy group, a substituted or unsubstituted acryloyl group, a substituted or unsubstituted methacryloyl group, a substituted or unsubstituted C2 to C30 alkenyl group, a substituted or unsubstituted C2 to C30 alkenyloxy group, a substituted or unsubstituted C2 to C30 alkynyl group, and a substituted or unsubstituted C2 to C30 alkynyloxy group.