Gala was born as Elena Ivanovna Diakonova (Russian: Елена Ивановна Дьяконова) in Kazan, Kazan Governorate, Russian Empire, to a family of intellectuals. Among her childhood friends was the poet Marina Tsvetaeva. She began working as a schoolteacher in 1915, at which time she was living in Moscow.
In 1912 she was sent to a sanatorium at Clavadel, near Davos in Switzerland for the treatment of tuberculosis. She met Paul Éluard while in Switzerland and fell in love with him. They were both seventeen. In 1916, during World War I she traveled from Russia to Paris to reunite with him; they were married one year later. Their daughter, Cécile, was born in 1918. Gala detested motherhood, mistreating and ignoring her child.
With Éluard, Gala became involved in the Surrealist movement. She was an inspiration for many artists including Éluard, Louis Aragon, Max Ernst and André Breton. Breton later despised her, claiming she was a destructive influence on the artists she befriended. She, Éluard and Ernst spent three years in a ménage à trois, from 1924-27. In early August 1929, Éluard and Gala visited a young Surrealist painter in Spain, the emerging Salvador Dalí. An affair quickly developed between Gala and Dalí, who was about 10 years younger than her. Nevertheless, even after the breakup of their marriage, Éluard and Gala continued to be close.
After living together since 1929, Dalí and Gala married in a civil ceremony in 1934, and remarried in a Catholic ceremony in 1958 in the Pyrenean hamlet of Montrejic. They needed to receive a special dispensation by the Pope because Gala had been previously married and she was a believer (not Catholic, but was an Orthodox Christian). Due to his purported phobia of female genitalia, Dalí was said to have been a virgin when they met on the Costa Brava in 1929. Around that time she was found to have uterine fibroids, for which she underwent a hysterectomy in 1936. She was Dalí's muse, directly inspiring and appearing in many of his works.
In the early 1930s, Dalí started to sign his paintings with his and her name as "(i)t is mostly with your blood, Gala, that I paint my pictures". He stated that Gala acted as his agent, and aided in redirecting his focus. According to most accounts, Gala had a strong sex drive and throughout her life had numerous extramarital affairs (among them with her former husband Paul Éluard), which Dalí encouraged, since he was a practitioner of candaulism. She had a fondness for young artists, and in her old age she often gave expensive gifts to those who associated with her.
In 1968, Dalí bought Gala the Castle of Púbol, Girona, where she would spend time every summer from 1971-1980. He also agreed not to visit there without getting advance permission from her in writing.
In her late seventies, Gala had a relationship and bond with millionaire multi-platinum rock singer Jeff Fenholt, former lead vocalist of Jesus Christ Superstar. Fenholt acted as a business representative for the Dalís in the United States, arranging sales of Dalí's work to Alice Cooper (a hologram), The Grateful Dead, short film, "Journey Through Upper Mongolia", short film, "Blood Is Thicker Than Honey", and others. Fenholt has stated that Gala told him from her hospital bed in Spain, that Dali had assaulted her, knocking her down and breaking her hip, which later resulted in her death.
Gala died in Port Lligat in the early morning of 10 June 1982, aged 87, and was buried in the Castle of Púbol in Girona, which Dalí had bought for her. In 1996, Gala's private castle in Púbol was opened to the public as the Gala-Dalí Castle House Museum.
Gala is a frequent model in Dalí's work, often in religious roles such as the Blessed Virgin Mary in the painting The Madonna of Port Lligat. His paintings of her show his great love for her, and some are perhaps the most affectionate and sensual depictions of a middle-aged woman in Western art. Among the paintings she served as a model for are: Imperial Monument to the Child-Woman, Gala; Memory of the Child-Woman; The Angelus of Gala; Gala and "The Angelus" of Millet before the Imminent Arrival of the Conical Anamorphoses; William Tell and Gradiva; The Old Age of William Tell; The Discovery of America by Christopher Columbus; The Ecumenical Council; Corpus Hypercubus; Galatea of the Spheres; and others.
In Portrait of Galarina, (1940–45) Gala's face is shown severe and confrontational, her bared breast meant to depict bread, and the snake on the arm a gift of Dalí's sponsor Edward James.