Olesya Yurivna Rulina is a Russian-American actress. She first hit the small screen in 2001 and plenty of roles followed, but she is best known for co-starring as Kelsi Nielsen in all three films of the High School Musical franchise. She also starred in the films "Private Valentine: Blonde & Dangerous"(2008), "Flying By" (2009), "Expecting Mary" (2010), and "Family Weekend" (2013).