Nathaniel Adderley Jr. (born May 23, 1955) is an American pop and rhythm and blues music arranger and pianist who spent much of his music career arranging as music director for Luther Vandross tours and contributed as co-songwriter on most of Vandross’s albums. His father Nat Adderley (1931–2000) was a composer and jazz cornet and trumpet player, while his uncle Cannonball Adderley (1928–1975) was a jazz alto saxophonist.

Nat Adderley Jr. was born in Quincy, Florida, on May 23, 1955. The scion of a famed jazz family, he grew up in Teaneck, New Jersey, moving to that suburban New York City community with his family when he was five years old. He started playing piano as a child and had his first song, “I’m on My Way”, recorded by his uncle Cannonball on the 1967 album Why Am I Treated So Bad! by the Cannonball Adderley Quintet when the young Nat Adderley was only 11 years old. While at the Fiorello H. LaGuardia High School of Music & Art and Performing Arts in New York City, Adderley first met Luther Vandross, who attended Taft High School in the Bronx. Adderley would end up spending much of his musical career with Vandross. He attended Yale University, graduating with a degree in African American studies.