Known best for her role as Cassietta Hetebrink on NBC's Amen, Montgomery also starred as Olivia Williams on ABC's Married People. Also a stage actress, she earned an Obie Award for her performance in the 1970s Off-Broadway production of My Sister, My Sister.
One of her first screen credits was in a 1976 made-for-TV movie titled The First Breeze of Summer.
She belonged to New York-based theater ensembles called the La Mama Experimental Theatre Club and the Negro Ensemble Company.
She was born and raised in Queens, New York.
She directed S. Epatha Merkerson and Ruby Dee in the 2013 film Mitote.