Gellar was born on Long Island. She is the only child of Rosellen (née Greenfield), a nursery school teacher, and Arthur Gellar, a garment worker. Both of her parents were Jewish, though Gellar's family also had a Christmas tree during her childhood. In 1984, when she was seven, her parents divorced and she was raised by her mother on the city's Upper East Side. While growing up with her mother, she lost contact with her father, from whom she remained estranged until his death in 2001; she once described him as "non-existent", and in the early 2000s, she stated: "My father, you can just say, is not in the picture. I'm not being deliberately evasive about him, it's just that there's so little to say. " Besides being a working child at the time, Gellar was a competitive figure skater to which she finished in third place at a New York State regional competition as well as having a black belt in taekwondo.