Her death from cancer was confirmed to Playbill by Ms. Shelley's close friend Barrie Kreinik.
Ms. Shelley made her Broadway debut as Gwendolyn Pigeon in the original Broadway cast of The Odd Couple in 1965, a role she would reprise in both the feature film and TV series adaptations of the Neil Simon play. Shelley shares the distinction of being one of only two actors (along with Monica Evans, who co-starred as her sister Cecily) to appear in all three major adaptations of The Odd Couple as the same characters.
She went on to enjoy a prolific career on Broadway, with a career that included roles both dramatic and comedic. Ms. Shelley earned her first Tony nomination in 1975 for her performance in Alan Ayckbourn's Absurd Person Singular.
However, it was Bernard Pomerance's Tony-winning 1979 play The Elephant Man that truly allowed Ms. Shelley to make her mark. She won the Tony Award for Best Actress in a Play (in a tie with Constance Cummings) and an Outer Critics Circle Award for her performance as Mrs. Kendal, the actor who befriends John Merrick.
Ms. Shelley won an Obie Award in 1982 for her performance in James Lapine's Twelve Dreams Off-Broadway at the Public Theater and was nominated for a Tony Award again in 1987 for her performance as Maxine in Richard Harris' farce Stepping Out.
In 2003, Ms. Shelley created the role of Madame Morrible, Elphaba's mentor and later chief adversary in the original company of Wicked. She returned to the role for five months beginning in August 2007, shortly before opening Billy Elliot The Musical on Broadway as Grandma in 2008. It was for this role that Ms. Shelley would receive her fourth and final Tony Award nomination, for Best Featured Actress in a Musical.
Ma. Shelley's final Broadway performance was in A Gentleman's Guide to Love and Murder. She replaced Jane Carr as Miss Shingle.
Though most of Ms. Shelley's career was spent on the stage, she worked in film as well, including an appearance alongside her Wicked co-star Kristin Chenoweth in 2005's Bewitched. Shelley also voiced several roles in Disney animated films, including the goose Amelia Gabble in 1970's The Aristocrats, Lady Kluck in 1973's Robin Hood, and Lachesis in 1997's Hercules.
Ms. Shelley was born August 16, 1939, in London, where she began her career in British films before coming to America. She was married to Albert G. Woods from 1967 until his death in 1971.