Phineas Newborn Jr. (December 14, 1931 – May 26, 1989) was an American jazz pianist, whose principal influences were Art Tatum, Oscar Peterson, and Bud Powell.

Newborn was born in Whiteville, Tennessee, and came from a musical family: his father, Phineas Newborn Sr., was a drummer in blues bands, and his younger brother, Calvin, a jazz guitarist. He studied piano as well as trumpet, and tenor and baritone saxophone.

Before moving on to work with Lionel Hampton, Charles Mingus, and others, Newborn first played in an R&B band led by his father on drums, with his brother Calvinon guitar, Tuff Green on bass, Ben Branch and future Hi Records star Willie Mitchell. The group was the house band at the now famous Plantation Inn Club in West Memphis, Arkansas, from 1947 to 1951, and recorded as B. B. King‘s band on his first recordings in 1949, as well as the Sun Records sessions in 1950. They left West Memphis in 1951 to tour with Jackie Brenston as the “Delta Cats” in support of the record “Rocket 88“, recorded by Sam Phillips and considered by many to be the first ever rock & roll record (it was the first Billboard No. 1 record for Chess Records).