Kuldar Sink (September 14, 1942 - January 29, 1995) was a Estonian composer. Sink was one of the youngest reformers of the Estonian music in the 1960s. He graduated from the Tallinn Music School in music theory in 1960 and flute in 1961, also studying composition under Veljo Tormis. From 1961–1966, he continued his composition studies at the Leningrad Conservatoire under Andrei Petrov. In 1960–1963 Sink worked as a flutist at the "Estonia" Theatre Orchestra, and in 1963–1973 at Estonian TV and Radio Symphony Orchestra. From 1973 to the end of his life, Sink was a freelance composer.