Cummings was born in Seattle, Washington, the only daughter and younger child of Kate Logan (née Cummings), a concert soprano, and Dallas Vernon Halverstadt, a lawyer. After her parents separated when she was 10 years old, she never saw her father. She attended St. Nicholas Girls' School in Seattle.
The San Diego Stock Company gave Cummings her initial acting opportunity in a "walk-on part" playing a prostitute in a 1926 production of Seventh Heaven.
She debuted on Broadway as a chorus girl, a member of the ensemble in Treasure Girl (1928) by the age of 18. While appearing on Broadway, she was discovered by Samuel Goldwyn, who brought her to Hollywood in 1931. Between 1931 and 1934, Cummings appeared in more than 20 films, including the Harold Lloyd films Movie Crazy and American Madness, directed by Frank Capra.
She was married to the playwright and screenwriter Benn Levy from 3 July 1933 until his death in 1973. Her husband being from Britain, Cummings moved there and continued acting, both in films and on the stage, in Britain. Few of her films were hits in the US, although Blithe Spirit, adapted from the Noël Coward play, was popular. Levy went on to write and direct films for Cummings, such as The Jealous God (1939); he also served in the UK Parliament from 1945 to 1950 as the Labour MP for Eton and Slough. They had a son and a daughter.
She played Mary Tyrone in the Royal National Theatre's production of Eugene O'Neill's Long Day's Journey into Night opposite Sir Laurence Olivier, to great acclaim, and later recreated the role for a television production.
In 1979, Cummings won the Tony Award for Best Actress in a Play for her performance as Emily Stilson in the drama Wings (1978–79) (written by Arthur Kopit), a play about a former aviator (Stilson) who has suffered a stroke, from which she struggles to recover. This role also brought her Obie and Drama Desk awards and an Olivier nomination. In 1982, she was nominated for a Drama Desk Award for Outstanding Actress in a Play for her work in The Chalk Garden.
On 1 January 1974, Cummings, who resided in Britain for many decades until her death, was made a Commander of the Order of the British Empire (CBE) for her contributions to the British entertainment industry.
She was a committee member of the Royal Court Theatre and the Arts Council. She has a star in the Motion Pictures section on the Hollywood Walk of Fame at 6201 Hollywood Boulevard. It was dedicated on February 8, 1960.
|1926||Seventh Heaven||prostitute||Stage debut in Seattle, WA|
|1928||Treasure Girl||chorus ensemble||Musical comedy||Broadway debut|
|1930||June Moon||Miss Rixey||Tin Pan Alley comedy|||
|1930||This Man's Town||Carrie||Drama|
|1934||Sour Grapes||first appearance on London stage.|
|1934||Accent on Youth||Linda Brown||Comedy|
|1936||Young Madame Conti||Nella Conti||Melodrama|
|1937||Madame Bovary Revival||Emma Bovary||Restoration Comedy|
|1938||If I Were You||Nellie Blunt||Farce|
|1938||Goodbye, Mr Chips||Katherine||Drama|
|1939||The Jealous God|
|1939–1940||Romeo and Juliet||Juliet||Tragedy|
|1939–1940||Old Vic Theatre Season|
|1939||Joan of Arc||Joan||Drama|
|1939||The Good Natur'd Man||Miss Richland||Drama|
|22 April 1940||Shakespeare Birthday Festival|
|1943||The Petrified Forest||Gabby||Drama|
|1945||One Man Show||Racine Gardner||Drama|
|1948||Don't Listen Ladies||Farce|
|1949||Before the Party||Laura||Comedy|
|1950||Return to Tyassi|
|1957||The Rape of the Belt||Antiope||played at Piccadilly Theatre (1957), and then Martin Beck Theatre, NY (1960).<ref>"Obituary of Constance Cummings". 26 November 2006. Retrieved 1 June 2017.|
|1965||Who's Afraid of Virginia Woolf?||Martha|
|1966||Public and Confidential|
|1967||Fallen Angels||Jane Banbury||Comedy|
|1969||The Milk Train Doesn't Stop Here Anymore||Mrs Flora Goforth||Tragedy|
|1970||The Visit||Claire Zachanassian||Tragi-comedy|
|1971||Amphitryon 38||Leda||Greek Drama|
|1971||Long Day's Journey into Night||Mary Tyrone|
|1971–1972||National Theatre, London, Repertoire Season||Classical drama|
|1972–1973||National Theatre, London, Repertoire Season|
|1973||The Cherry Orchard||Madame Ranevsky|
|1974||National Theatre, London, Repertoire Season|
|1979||Wings||Emily Stilson||Tony Award, Obie Award, Drama Desk Award|
|1979||National Theatre, London, Repertoire Season|
|1981||The Golden Age|
|1985||The Glass Menagerie|
|1986||Fanny Kemble at Home|
|1992||The Chalk Garden||Mrs St Maugham||Her last appearance on Broadway|
|1996–1999||Uncle Vanya||Maman||Her last stage appearance.|