Nina Kuscsik (born January 2, 1939) is a retired female long-distance runner from the United States.
She was the first woman to officially win the Boston Marathon, 1972. Alongside Beth Bonner, Kuscsik became the second American woman to complete a marathon in under three hours, running a time of 2:56:04 at the 1971 New York City Marathon (Bonner did so in the same race with 2:55:22).
Kuscsik is a former American women's record-holder for a 50-mile run, through her run of 6:35:53 in 1977 in Central Park, New York. She continued running into her later years and was the first woman to finish the Empire State Building Run-Up in 1979, 1980 and 1981.
Before she took up running, she was New York State women's speed skating champion, New York State women's roller-skating champion, and New York State women's bicycling champion, all in same year. She was instrumental in influencing the U.S. Amateur Athletic Association, in late 1971, to increase its maximum distance for sanctioned women's races, leading to official participation by women in marathons, beginning at Boston in 1972.