Robert L. Green earned his B.A. in Psychology in 1958 and his M.A. in School Psychology in 1960 from the San Francisco State College. Green earned his Ph.D. in Educational Psychology from Michigan State University in 1963. Green has been affiliated with MSU since 1960, and served as a graduate assistant, assistant instructor and instructor in the Education Department. While a Professor of Educational Psychology at MSU in 1968, Green was named the director of the Center for Urban Affairs. He became the Dean of the College of Urban Development when it was created in 1972, the first black dean at MSU. From 1983-1985 he served as the president of the University of the District of Columbia in Washington, D.C.

While at MSU, he helped push for affirmative action hiring programs and was an outspoken civil rights activist. On a sabbatical leave to the Middle East and East Africa in 1971-1972, he served as a visiting lecturer at Hebrew University of Jerusalem and the University of Nairobi in Kenya, lecturing on the status of education for the disadvantaged in the United States.

During a leave of absence from MSU between 1965-1966, Green served as the Education Director of the Southern Christian Leadership Conference, working closely with Dr. Martin Luther King Jr.