Oscar Hernandez (born March 22, 1954) is a Puerto Rican musician, musical arranger and producer.

Hernandez's family moved to the United States from Puerto Rico in the 1940s, in search of a better way of life. They settled down in the South Bronx, a ghetto, which is a section that is heavily populated by latinos in New York where Hernandez was born. Hernandez who was the youngest of eleven siblings, received his primary and secondary education in the city's public school system.

As a child he was exposed to the music of Tito Puente, Tito Rodriguez and Willie Colon among others. He would also sneak into nightclubs to watch and listen to the music of Ray Barretto, Eddie Palmieri and Richie Ray. Hernandez was determined to leave the ghetto after witnessing the death of one of his brothers from a drug overdose. In 1966, he took trumpet playing classes at a local Boys Club. Two years later someone gave his brother a piano, which he kept in the basement of the apartment building where the family lived. Some of the local musicians, who would get together and jam in the basement, showed Hernandez the basics of piano playing, the rest was self-taught.