Seldes studied with Sanford Meisner, Katharine Cornell, and Martha Graham. Actor Laura Linney said, "Marian is our touchstone to those theatrical ancestors. She provides an inspiration that makes you want to reach outside of yourself to something more potent and powerful." Seldes was a member of the drama faculty of The Juilliard School from 1967 to 1991. Her students included Christopher Reeve, Robin Williams, Kelsey Grammer, Kevin Kline, william Hurt, Patti LuPone, Val Kilmer, and Kevin Spacey. In 2002, Marian Seldes began teaching at Fordham University, Lincoln Center.