Sunil Santha (Sinhala:සුනිල් ශාන්ත) (14 April 1915 - 11 April 1981) was a renowned and influential Sri Lankan composer, singer and lyricist. He was pivotal in the development of Sinhala music and folk songs in the mid to late 1940s and early 1950s. He composed the beloved soundtracks to Lester James Peries' Rekava and Sandesaya in 1956 and 1960. In a later comeback he produced several experimental works.

Sunil Santha was born on April 14, 1915 on the Sinhala New Year's Day in Dehiyagatha, Jaela. Both his parents died before he was two years old, and Santha was raised by his grandmother. At an early age he came to the limelight when he played king Dutugamunu in a village play. One villager adorned him with a battery-powered lighted necklace.

Santha passed the school leaving certificate examination as the first in the island, with the highest marks in his class as a young adult and was awarded the Weeraratne award. In 1933 he completed the Teachers Final Examination and began work as a teacher at the Mt. Calvary School. While tenured there, Santha led the school to three consecutive victories at the Southern Schools Music Competition. In 1939 he passed the Intermediate Gandarva Examination and received a certificate in physical training. He also learned to play the piano and guitar at that time. He acted and produced several dramas including "Hamlet" during this period.