Marthaniel “Marcus” Roberts (born August 7, 1963) is an American jazz pianist, composer, arranger, bandleader, and teacher.

Roberts was born in Jacksonville, Florida, United States. His mother was a gospel singer who had gone blind as a teenager, and his father was a longshoreman. Blind since the age of five due to glaucoma and cataracts, he started learning the piano at age five by picking out notes on the instrument at his church until his parents bought a piano when he was eight. He attended the Florida School for the Deaf and the Blind in St. Augustine, Florida, the alma mater of blind pianist Ray Charles. Roberts began teaching himself to play piano at an early age, having his first lesson at age 12, and then studying the instrument with pianist Leonidas Lipovetsky while attending Florida State University.