Larisa was born in Santa Clara County, California, to Lorraine (Allen), a nurse, and Roman Oleynik, an anesthesiologist. Her father is of Ukrainian and Slovak descent.
Larisa's big break came when she was eight. She had gotten the part of young Cosette in a production of "Les Miserables". Her costar was Rider Strong, playing Gavroche. The two would be reunited when Larisa guested on Rider's sitcom, Incorrigible Cory (1993). Larisa's most well known roles are Bianca in 10 bonnes raisons de te larguer (1999), and Alex in The Secret World of Alex Mack (1994).
