Olesya Yurivna Rulina is a Russian-American actress. She is best known for co-starring in all three films of the High School Musical franchise as Kelsi Nielsen. She also starred in the films Private Valentine: Blonde & Dangerous (2008), Flying By (2009), Expecting Mary (2010) and Family Weekend (2013).

High School Musical is an American media franchise centered on a series of musical romantic comedy-drama films created by Peter Barsocchini. The franchise also includes stage musicals, books, comics, live shows, video games, and a television series.