Marian Seldes, who has died aged 86, was a much-loved, genuine star, even though almost always in supporting roles, and the essence of Broadway theatre for several decades in plays by Edward Albee, Ira Levin and Peter Shaffer. She rarely left Manhattan, New York, taught at the Juilliard School and lived in an apartment overlooking Central Park.
Seldes never played in London, but worked with many leading UK directors, from John Gielgud on her Broadway debut in Medea with Judith Anderson (1947) to Michael Blakemore in her final New York stage appearance, opposite Angela Lansbury in Terrence McNally's Deuce (2007).
This latter play offered the chance to see two highly skilled veterans at the top of their game, just about, even though they were playing former tennis champions reminiscing at the side of the court during a tournament in Flushing Meadow. Seldes, always elegant in posture and movement, blessed with a liquid velvety voice with a sharp cutting edge, was the most brilliant of upstaging foils to Lansbury.
Seldes was intriguing on stage because you sensed she had done so much in her life. On my first visit to New York as a critic, in 1983, I saw her as a domineering matriarch in Tina Howe's Painting Churches. Each time I returned, I hoped she would be on the bill again. Her beam was so strong, she would radiate right through to the foyer. Her imperfect, idiosyncratic beauty, her style and richness of personality, meant that she was always extraordinary. And she was never famous for underplaying. Ben Brantley, the New York Times drama critic, said that she made going over the top feel like a trip to the moon.
Born in Manhattan, she was the daughter of Gilbert Seldes, an author and critic, of Russian Jewish immigrant stock (the Gershwins and Irving Berlin were family friends), and Alice Wadhams Hall, a socialite. At the age of six, Marian was involved in a motorboat accident which left her with facial scars, but she was never deterred from the theatre. She trained in ballet and hung up her pumps in 1946 to study with Sanford Meisner at the Neighbourhood Playhouse.
Seldes worked in television from 1952 but always felt most at home on stage, and made a striking impression in Jean Giraudoux's Ondine, starring Audrey Hepburn and Mel Ferrer, in 1954. Ten years later, she was Tallulah Bankhead's troubled secretary in Tennessee Williams's The Milk Train Doesn't Stop Here Anymore.
Her association with Albee began when she understudied Irene Worth in Tiny Alice on Broadway in 1965. In the following year, she won a Tony award for her performance as the hysterical daughter of feuding parents – played by Hume Cronyn and Jessica Tandy – in Albee's lacerating A Delicate Balance. This was her watershed moment.
Her dance training with Martha Graham paid off in the title role of a 1977 play irresistibly titled Isadora Duncan Sleeps with the Russian Navy. Ira Levin's Deathtrap opened in 1978, and she played every single performance for five years, earning a mention in the Guinness Book of Records as a "most durable" actor. And she had warmed up for that stint by playing a mere 900 performances in the entire three-year run of Shaffer's Equus from 1974, opposite first Anthony Hopkins then Richard Burton, Leonard Nimoy and Anthony Perkins.
Classic roles included notably Queen Margaret in a production of Richard III starring Kevin Kline in Central Park in 1983, and in Chekhov's Ivanov at Lincoln Centre and Anouilh's Ring Round the Moon in the 1990s. Her other Albee appearances were in the off-Broadway premieres of Three Tall Women (1994), The Play About the Baby (2001) and Counting the Ways (2003); in the last of these she took a role first played in London (at the National Theatre in 1976) by Beryl Reid and then by Lansbury in Hartford, Connecticut. She became as renowned a Broadway star and teacher as her great heroines, Katharine Cornell (in whose honour she named her daughter, Katharine), Helen Hayes and Uta Hagen. At the Juilliard, where she taught between 1967 and 1991, her students included Christopher Reeve, Robin Williams, Patti LuPone and Kelsey Grammer; she began teaching at Fordham University, Lincoln Centre, in 2002.
Occasional movies included George Stevens's The Greatest Story Ever Told (1965), Peter Chelsom's Town and Country (2001), co-starring Warren Beatty, Diane Keaton and Charlton Heston, and Mike Newell's Mona Lisa Smile (2003), with Julia Roberts, Maggie Gyllenhaal and Juliet Stevenson.
She was inducted in the American Theatre Hall of Fame in 1995 and awarded a second Tony, for lifetime achievement, in 2010. Acting, she said defined her life and gave it shape and form: "All I've done is live my life in the theatre and loved it … If you can get an award for being happy, that's what I've got."
She is survived by Katharine, the daughter of her first marriage to Julian Claman, which ended in divorce. Her second husband, Garson Kanin, died in 1999.
• Marian Hall Seldes, actor, born 23 August 1928; died 6 October 2014