Grayson was born in the Bronx, New York City, New York, to Dorothy Ann (née Sabin) and Daniel Franklin Grayson.[6][7] He graduated from Bronx High School of Science in 1975. Grayson worked his way through Harvard College as a janitor and nightwatchman. He graduated magna cum laude and Phi Beta Kappa with a Bachelor of Arts degree with a Special Concentration in Urban Studies in 1978.[8][9] After working two years as an economist, he returned to Harvard for graduate studies.[10] In 1983, he earned a Jurisdoctorate cum laude from Harvard Law School and a Masters of Public Policy from the John F. Kennedy School of Government. Additionally, he completed some of the requirements for a PhD in government—the course work and passing the general exams.[8][11][12]