Marian Hall Seldes was an American actress. A five-time Tony Award nominee, she won the Tony Award for Best Featured Actress in a Play for A Delicate Balance in 1967, and received subsequent nominations for Father's Day (1971), Deathtrap (1978–82), Ring Round the Moon (1999), and Dinner at Eight (2002). She also won a Drama Desk Award for Father's Day.

The Tony Award for Best Featured Actress in a Play is an honor presented at the Tony Awards, a ceremony established in 1947 as the Antoinette Perry Awards for Excellence in Theatre, to actresses for quality supporting roles in a Broadway play. The awards are named after Antoinette Perry, an American actress who died in 1946. Honors in several categories are presented at the ceremony annually by the Tony Award Productions, a joint venture of The Broadway League and the American Theatre Wing, to "honor the best performances and stage productions of the previous year."