Carol Alt(supermodel)- topless in Deadly Past(1988), and Family Matters(1983).
Bijou Phillips(model-singer)- Topless in Black + White (2000) Topless+ full frontal in Bully (2001)- ? inHavoc (2004).
Paulina Porizkova (supermodel)- nip slip in Her Alibi(1989). Topless in Thursday (1998) and Knots (2004)
Rebecca Romijn-(Stamos) (supermodel)- Topless in Rollerball(2001), Topless and Full Frontal in Femme Fatale (2002), topless in Godsend (2004).
Milla Jovovich (model-singer-musician)- topless in Chaplin (1992), The Fifth Element (1997), He Got Game (1998), Topless and Full frontal in Resident Evil (2002) and No Good Deed (2002), and topless in Resident Evil: Apocalypse(2004).
Cybill Shepherd(model)- Topless and bare butt in The Last Picture Show (1971).
Vitamin C(Colleen Fitzpatrick) Singer- Topless in Dracula 2000 (2000).
Vanity(Denise Mathews)- Singer- Topless in Tanya's Island (1980), 52 Pick Up (1986), Never Too Young to Die (1986), and Action Jackson (1988).
Nicole Appleton+ Natalie Appleton (singers-All Saints)- Both topless in Honest (2000).
Appolonia (singer)- Topless in Amor Ciego (1980), Purple Rain (1984), and Black Magic Woman (1991).
Jamie(James)King(model)- Topless in Happy Campers (2000) and Sin City (2005).
Lori Singer (model-classical cello player)-Topless in Trouble in Mind(1986), Summer Heat (1987), Made in U.S.A.(1988), Sunset Grill (1993), topless + full frontal in Short Cuts (1993), topless in The Last Ride (1994).
The following were former models who appeared nude in films, but I'm not sure they qualify as supermodels: