Márta Károlyi (Hungarian: ['ma?rt? 'ka?roji]; née Eross; born August 29, 1942) is a Romanian-American gymnastics coach and the former national team coordinator for USA Gymnastics.
She and her husband, Béla, are ethnic Hungarians from Transylvania, Romania, and trained athletes in Romania, but defected to the United States in 1981.
Béla and Márta Károlyi have trained nine Olympic champions, fifteen world champions, sixteen European medalists and many U.S.
national champions, including Mary Lou Retton, Betty Okino, Kerri Strug, Teodora Ungureanu, Phoebe Mills, Nadia Comaneci, Kim Zmeskal, and Dominique Moceanu.