From Scarlett and Gisele to Ashton and Kiefer, VIEW OUR GALLERY of stars and their secret siblings, as the annual Twins Day Festival kicks off tomorrow.
Craig Ambrosio, Icon SMI / Newscom
José and Ozzie Canseco
Craig Ambrosio, Icon SMI / Newscom
Gisele and Patricia Bundchen
Newscom
Ashton and Michael Kutcher
Tom Vickers / Splash News
Isabella and Ingrid Rossellini
Express / Getty Images
Jerry and Terry Hall
Retna
Jill and Jacqueline Hennessy
Ron Galella, WireImage / Getty Images
Jon and Daniel Heder
Frazer Harrison / Getty Images
Kiefer and Rachel Sutherland
AP Photo; George Pimentel, WireImage / Getty Images