Playbill confirmed the news on social media.
Starring opposite Harold Lang and Vivienne Segal, she won the Tony for Best Featured Actress in a Musical.
She also performed in revivals of such classics asGuys and DollsandBrigadoon.
Helen Gallagher in ‘Roseland’ (1977)Everett Collection
The show ran from January 1971-February 1973 at the 46th Street Theatre (now the Richard Rodgers Theatre).
She returned to Broadway in the 1972-73 production of ShakespearesMuch Ado About Nothingbefore landing her biggest screen role.
She also scored two other nominations in the category in 1979 and 1981.
Helen Gallagher and Bernard Barrow in ‘Ryan’s Hope’ABC/Everett Collection
She also was a longtime member of the faculty at Herbert Berghof Studio in Manhattan.
