A talented member of the Actors Studio, Marchand made her Broadway debut in The Taming of the Shrew in 1951. Additional theatre credits include The Merchant of Venice, Love's Labour's Lost, Much Ado About Nothing, Forty Carats, And Miss Reardon Drinks A Little, The Plough and the Stars, The Glass Menagerie, Morning's at Seven, Awake and Sing!, The Octette Bridge Club, Love Letters, Man and Superman, The Importance of Being Earnest, The School for Scandal, The Balcony, for which she won a Distinguished Performance Obie Award, and Black Comedy/White Lies, for which she was nominated for the Tony Award for Best Performance by a Leading Actress in a Play. She was nominated four times for the Drama Desk Award, winning handily for Morning's at Seven. She won a second Obie for her performance in A. R. Gurney's The Cocktail Hour.