Dennis was devoted to the cause of animal welfare. She rescued stray cats from the bowels ofGrand Central Terminal. At the time of her death in Westport, Connecticut, she lived with more than 20 cats, who were adopted out by longtime friends to new homes.
Dennis achieved Broadway fame with her leading role inHerb Gardner'sA Thousand Clowns (1962–63), for which she won a Tony award for her performance. She was replaced in the 1965 film version byBarbara Harris.[7] The show ran for 428 performances.[8]
Around this time, Dennis guest-starred on episodes of the TV seriesNaked City ("Idylls of a Running Back", 1962, "Carrier", 1963),The Fugitive ("The Other Side of the Mountain", 1963),Arrest and Trial ("Somewhat Lower Than the Angels" 1964), andMr. Broadway ("Don't Mention My Name in Sheboygan", 1964).[9] She was the lead of the Broadway comedyAny Wednesday (1964–66), which ran for 983 performances[10] and won her a second Tony.[7]
Dennis' first lead role in a movie was inUp the Down Staircase (1967), directed byRobert Mulligan. In his review forThe New York Times,Bosley Crowther cited her for "a vivid performance of emotional range and depth … engagingly natural, sensitive, literate and thoroughly moving."[12] The film was a box-office success, as wasThe Fox (1967), directed byMark Rydell, despite its controversial subject matter. In 1967 Dennis was voted the 18th biggest star in the US.[13]
Dennis briefly returned to Broadway to star inDaphne in Cottage D (1967), which had a short run.
She starred inSweet November (1968) as a woman who takes multiple lovers, and made a TV version of the playA Hatful of Rain (1968).
In the mid- and late 1980s, Dennis acted less, owing to growing health problems. She appeared on TV inYoung People's Specials ("The Trouble with Mother", 1985),The Love Boat ("Roommates/Heartbreaker/Out of the Blue", 1985),Alfred Hitchcock Presents ("Arthur, or the Gigolo", 1985) andThe Equalizer ("Out of the Past", 1986). In motion pictures, she had supporting roles in a 1986 remake ofLaughter in the Dark, which was never completed,Woody Allen'sAnother Woman (1988), and the horror films976-EVIL (1989) andParents (1989).
Her final role was in the crime dramaThe Indian Runner, filmed in 1990 and released in 1991. The movie markedSean Penn's debut as a film director. ActorViggo Mortensen, who played one of her two sons, wrote of the preparations for the movie and filming in the vicinity ofOmaha, Nebraska:
When I first met with Sean Penn and his producer,Don Phillips, to discuss the possibility of my playing Frank, one of the first questions I asked them was who, if anyone, they had in mind to play the mother. When Sean answered that he did not want to consider anyone other than Sandy Dennis for the part, I couldn't have been happier, or more in agreement. Aside from my feelings for her as a friend, I believed she would be a great asset to the movie and would inspire us all to do our best. This proved to be true.As it turned out, most of her work was cut from the movie. This was not due to any shortcoming on her part. On the contrary, she was brilliant throughout … She was working on a level far above the rest of us. The concentration and vulnerability that she invested in the scene were remarkable. Heart-breaking. The fact that most of us knew that she was dying of ovarian cancer as she showed us the emotional disintegration of the character made the experience all the more poignant.[15]
Dennis lived with prominent jazz musicianGerry Mulligan from 1965 to 1974. In October 1965, her hometown newspaper,The Lincoln Star, published anAssociated Press article stating she and Mulligan had married in Connecticut in June of that year.[16] In a 1989 interview withPeople, however, Dennis admitted that they only pretended to be married after she unintentionally became pregnant.[3] Dennis miscarried, adding, "If I'd been a mother, I would have loved the child, but I just didn't have any connection with it when I was pregnant ... I never, ever wanted children. It would have been like having an elephant."[3]
From 1980 to 1985, Dennis lived with actorEric Roberts, 19 years her junior. On June 4, 1981, her German Shepherd was riding with Roberts when he crashed his vehicle into a tree. Roberts, who was under the influence of cocaine at the time, was in a coma for 72 hours and had to withdraw from the Broadway showMass Appeal.[17] Dennis' dog survived the accident.[3] She and Roberts were engaged to be married in spring 1983, but the ceremony never took place.[18] In his 2024 autobiographyRunaway Train, Roberts wrote that he too had impregnated Dennis, but she got an abortion.[19]
Dennis' sexual orientation was a matter of public discussion as early as 1968, when the scandal magazineUncensored ran a story that labeled her a lesbian.[20] In an article published less than four years after Dennis' death, Eric Roberts identified her as bisexual.[21][22][23][24] According to Roberts, Dennis told him she had many lesbian relationships and that she "appreciated the beauty of women. But she also liked and appreciated what a very, very young man could do to a woman, I suppose."[25]
During Dennis' lifetime, in-depth published interviews with her, such as one withThe Christian Science Monitor during her stint performing in an ensemble cast at theJohn F. Kennedy Center for the Performing Arts in 1981, made no mention of close relationships with women. That interview included the following exchange between journalist Louise Sweeney and Dennis about her marital status:
Dennis' grave at Lincoln Memorial Park
At one point I say, "When you were married to Gerry Mulligan ..." but she breaks in, tersely: "I was never married to anybody." I point out that "Who's Who" says she was married to Mulligan.
She says, "It's not—I'm not fussy about that—the truth is I was never married. We had a long association but we never married..."
But there it is inCurrent Biography: "In June, 1965, after a three-week courtship, Sandy Dennis was married to Gerry Mulligan, the jazz saxophonist and composer."
She sits bolt upright and repeats: "I've never been married. And I'm not fussy about it. It's just the truth is, that I was never married. It isn't true that I was ever married, which means that I never got a divorce. The newspapers jumped to that conclusion. It's so hard to get to somebody and say ... Oh, they're so funny about it."[26]
Dennis died fromovarian cancer on March 2, 1992, at her home inWestport, Connecticut, at age 54.[28] She was cremated and inurned at Lincoln Memorial Park in Lincoln, Nebraska.