Farmer was born in Seattle, to Ernest Melvin Farmer and Cora Lillian (Van Ornum) Farmer. Although her father was a prominent lawyer, Farmer displayed independence through her work roles as an usherette in a cinema, a waitress, a tutor and a factory worker. Farmer used the money earned from such employment to pay for her university fees, before winning a popularity contest that rewarded her with a trip to Europe.
In 1935, as a student at the University of Washington, Farmer won a subscription contest for the leftist newspaper, The Voice of Action. The first prize was a trip to the Soviet Union—Farmer accepted the prize, despite her mother's strong objections, so that she could see the pioneering Moscow Art Theatre. Farmer's interest in such topics fostered speculations that Farmer was not only an atheist, but a Communist as well.
Farmer proceeded to study drama at the University of Washington (UW) and, during the 1930s, the university's drama department productions were considered citywide cultural events and were frequented accordingly. While a student at UW, Farmer starred in numerous plays, including Helen of Troy, Everyman, and Uncle Vanya. In late-1934, she starred in the UW production of Alien Corn, in which she spoke foreign languages and played the piano—the production received rave reviews and was the longest-running play in the drama department's history at the time.
Returning from the Soviet Union in the summer of 1935, Farmer stopped in New York City, U.S., hoping to launch a legitimate theater career. Instead, she was referred to aParamount Pictures talent scout, Oscar Serlin, who arranged for a screen test. Paramount offered her a 7-year contract. Farmer signed it in New York on her 22nd birthday and moved to Hollywood. She had top billing in two well-received 1936 B-movies. She wed actor Leif Erickson in February 1936 while shooting the first of the movies, Too Many Parents. Later that year, Farmer was cast opposite Bing Crosby in her first "A" feature, Rhythm on the Range. During the summer of 1936, she was loaned to Samuel Goldwyn to appear inCome and Get It, based on the novel by Edna Ferber. Both of these films were sizable hits, and her portrayals of both the mother and daughter in Come and Get It were praised by the public and critics, with several reviews greeting Farmer as a new found star.
Farmer was not entirely satisfied with her career, however. She felt stifled by Paramount's tendency to cast her in films which depended on her looks more than her talent. Her outspoken style made her seem uncooperative and contemptuous. In an age when the studios dictated every facet of a star's life, Farmer rebelled against the studio's control and resisted every attempt they made to glamorize her private life. She refused to attend Hollywood parties or to date other stars for the gossip columns. However, Farmer was sympathetically described in a 1937 Colliers article as being indifferent about the clothing she wore and was said to drive an older-model "green roadster".
Hoping to enhance her reputation as a serious actress, she left Hollywood in 1937 to do summer stock in Westchester, New York. There she attracted the attention of directorHarold Clurman and playwright Clifford Odets. They invited her to appear in the Group Theatre production of Odets' play Golden Boy. Her performance at first received mixed reviews, with Time magazine commenting that she had been miscast. Due to Farmer's box office appeal, however, the play became the biggest hit in the Group's history. By 1938, when the production had embarked on a national tour, regional critics from Washington D.C. to Chicago gave her rave reviews.
Farmer had an affair with Odets, but he was married to actress Luise Rainer and did not offer Farmer a commitment. Farmer felt betrayed when Odets suddenly ended the relationship; and when the Group chose another actress for its London run—an actress whose family funded the play—she came to believe that The Group had used her drawing power selfishly to further the success of the play. She returned to Hollywood, and arranged with Paramount to stay in Los Angeles for three months out of every year to make motion pictures. The rest of her time she intended to use for theater. Her next two appearances on Broadway had short runs. Farmer found herself back in Los Angeles, often loaned out by Paramount to other studios for starring roles. At her home studio, meanwhile, she was consigned to costarring appearances, which she often found unchallenging.
By 1939, her temperamental work habits and worsening alcoholism began to damage her reputation. In 1940, after abruptly quitting a Broadway production of a play by Ernest Hemingway, she starred in two major films, both loan-outs to other studios. A year later, however, she was again relegated to co-starring roles. In mid-1941 Clifford Odets attempted to lure her back to Broadway to star in his upcoming play Clash by Night, but she refused, telling him she thought she needed to stay in Hollywood to rebuild her career. She next appeared opposite Tyrone Power in the film Son of Fury (1942) (on loan-out to Twentieth Century-Fox) and received critical praise for her performance. Despite this, though, Paramount canceled her contract in 1942, reportedly because of her alcoholism and increasingly erratic behavior during pre-production of Take a Letter, Darling. Meanwhile, her marriage to Erickson had disintegrated and ended in divorce in 1942.
From 1958 to 1964 Farmer hosted a successful TV show called Frances Farmer Presents which had the top audience ranking in its time slot throughout its run. She was also in demand as a public speaker. During the early 1960s Farmer was actress-in-residence at Purdue University and appeared in some campus productions. By 1964 her behavior had turned erratic again. Farmer was fired, re-hired and fired from her television program. The manager of that television station later suggested (in a 1983 interview) that her turn for the worse was triggered by an appearance he had arranged for her on NBC's The Today Show. He had hoped to get her good publicity but believed Farmer had been stressed by being asked on national television about her years of institutionalization.
Farmer's last acting role was in The Visit at Loeb Playhouse on the Purdue University campus in West Lafayette, Indiana, which ran from October 22 to October 30, 1965. She was arrested for drunk driving during this engagement.
Farmer had for years avoided contact with children. However, in the summer of 1958, she became attached to the five little daughters of a friend, and this helped to ease her guilt. One of the girls, nestling against her, whispered in her ear, "I love you so much, because you're good." Farmer was deeply moved: "No one had ever said that to me before. No one had probably ever thought it, for that matter, and it was there, at that moment, that a heart chiseled of stone melted." When the girl left, Farmer burst into tears and it seemed to her that all the evil that had surrounded her was being washed away. She felt that God had come into her life and sensed that she "would have to find a disciplined avenue of faith and worship". Shortly after, she found herself sitting in St. Joan of Arc Catholic church and petitioned that very day to begin her instructions and in 1959 was baptised into the Roman Catholic faith. Farmer had a great affection for St. Joan of Arc Church and attended services there regularly. During this period, she gave up drinking.
In 1970, Farmer died from esophageal cancer. She is interred at Oaklawn Memorial Gardens Cemetery in Fishers, Indiana. Jean Ratcliffe is buried in the same cemetery.