Grachan Moncur II (sometimes credited as Grachan Moncur) (born September 2, 1915, Miami, Florida - died November 3, 1996, Miami) wa an American jazz bassist with the Savoy Sultans. He is the half-brother of Al Cooper and the father of jazz trombonist Grachan Moncur III.
Moncur was a multi-instrumentalist as a teenager, learning trombone, tuba, and double bass while growing up in Miami. After moving to Newark, New Jersey, he began playing bass on a local radio station, where John Hammond heard him. Hammond brought Moncur in for studio sessions in 1935–36 with Mildred Bailey, Bunny Berigan, Putney Dandridge, Bud Freeman, and Teddy Wilson. He was a founding member of the Savoy Sultans, playing with the group until 1945. Later in the 1940s, he worked with Ike Quebec and Ace Harris.
Moncur moved back to Miami in the 1950s, where he remained active until late in the 1960s.