Diane Keaton as Kay Adams in The Godfather
|First appearance||The Godfather|
|Last appearance||The Godfather's Revenge|
|Created by||Mario Puzo|
|Portrayed by||Diane Keaton|
|Spouse||Michael Corleone (1951–60, divorced)|
|Children||Mary Corleone, Anthony Corleone|
|Religion||Roman Catholic (converted from Baptist)|
Kay is a native of Hanover, New Hampshire, and the only child of a Baptist minister and his wife. She is also the longtime girlfriend and eventual second wife of Michael Corleone (Al Pacino), the youngest son of Don Vito Corleone (Marlon Brando), the head of the Corleone crime family.
In 1945, while attending Dartmouth College, Kay meets and falls in love with Michael, also a student there. As a non-Italian, she is an outsider to the Corleones' world, and symbolizes Michael's initial desire to live a more Americanized and honest life, separate from his family's. When she and Michael attend the wedding of his sister, Connie (Talia Shire), they sit at a table away from the family. In the novel, the other guests notice how Kay's manner is freer than expected from an unmarried woman.
Kay is initially unaware that the Corleones are a powerful Mafia family. When the famous singer Johnny Fontane (Al Martino) arrives at Connie's wedding reception, Kay, a fan, is surprised that Michael knows him, then stunned when he relates how his father "helped" his godson Johnny's early career by threatening to kill his manager unless he released Fontane from his contract.
After a failed assassination attempt on his father, Michael murders the culprit, drug lord Virgil Sollozzo (Al Lettieri), and Captain Mark McCluskey (Sterling Hayden) a corrupt NYPD officer on Sollozzo's payroll. Michael flees to Sicily, where he falls in love with and marries a young local woman, Apollonia Vitelli (Simonetta Stefanelli). Kay has no knowledge of Michael's whereabouts or his marriage, and eventually returns to her hometown to work as a teacher. She asks the Corleone family's consigliere Tom Hagen (Robert Duvall) to deliver a letter to Michael, but Hagen refuses lest it be used in court proceedings as proof the family had "knowledge of his whereabouts". During this time, Kay develops a close relationship with Michael's mother, Carmela (Morgana King).
Apollonia is killed in a car bombing that targeted Michael. After recovering from his injuries, Michael returns to the United States. More than a year following his return, Michael seeks out Kay, wanting to reunite with her, although she is dismayed that he now works for his father. They marry after he promises her the Corleone family will be completely legitimate within five years.
Kay and Michael have two children, Anthony and Mary. (In the novel, they have two boys.) They are born within two years of each other, leading Michael to joke that Kay is "more Italian than Yankee". Kay retorts that Michael is "more Yankee than Italian", because he always takes his work home with him.
Michael becomes Don in 1955, after Vito's death. His first act is to order the assassinations of the Dons of the other Five Families and Connie's abusive husband Carlo Rizzi (Gianni Russo), who had participated in a plot to murder Vito's eldest son Sonny eight years before. When a distraught Connie accuses Michael of orchestrating Carlo's murder, Kay asks Michael if it is true. Michael denies any involvement. However, immediately afterward, Kay observes Michael receiving his caporegimes. One of them, Peter Clemenza, (Richard Castellano) respectfully greets him as the new Don. Kay realizes Connie was telling the truth and that Michael has become his father's successor in every way.
In the novel, Kay flees to New Hampshire with their children, despite Connie's recanting her accusations. Hagen, at Michael's request, persuades her to return. Hagen risks his own life by revealing to Kay some Corleone family secrets and "hypothetical" reasons for Michael's actions.
Kay converts to Catholicism and attends Mass daily to pray for her husband's soul (just as Carmela Corleone had done for Vito). An early draft of the film's script ended with Kay's lighting candles for Michael.
At the beginning of The Godfather Part II (set in 1958-60), Kay, who is pregnant with the couple's third child, implores Michael to fulfill his promise to legitimize the family business. Michael continues making a genuine effort to eliminate the family's criminal ties. However, his escalating war with rival Hyman Roth (Lee Strasberg), as well as his growing obsession with revenge, keeps him trapped in the criminal underworld. On the night after Anthony's First Communion, assassins machine gun Michael and Kay's bedroom; the couple barely escapes unharmed. Not long afterward, Kay suffers an apparent miscarriage.
Kay grows increasingly disgusted with Michael's criminal life; in particular, she is appalled that Michael's button men are Anthony's closest companions. Kay becomes convinced that Michael will always live in a world of crime and violence. During the U.S. Senate hearing on organized crime that is being held in Washington D.C., Kay tells Michael she is leaving him and taking the children. During the ensuing argument, she reveals that her "miscarriage" was actually an abortion and that she had the procedure to avoid bringing another of Michael's sons into the world. Enraged, Michael hits Kay and takes custody of their children; the two divorce soon afterward.
Michael initially prevents Kay from seeing their children. When she secretly visits them (with Connie's help), Michael coldly closes the door on her.
By the time of The Godfather Part III (set in 1979–80), Kay is remarried to a prosecutor named Douglas Michelson; Michael had granted Kay custody of Anthony (Franc D'Ambrosio) and Mary (Sofia Coppola). Michael and Kay, who have not seen each other since 1971, have an uneasy reunion at a family gathering. Anthony informs Michael he wants to quit law school to become an opera singer. Kay supports his decision, but Michael wants his son to finish his studies or go into the "family business" (a legitimate charitable foundation). An argument ensues, in which Kay tells Michael that both she and Anthony know about Michael's having ordered his brother Fredo (John Cazale)'s murder 20 years earlier (as portrayed at the end of the previous film). She says she "dreads" him, but they reach a truce after Michael agrees to let Anthony leave school.
When Michael suffers a stroke, Kay visits him in the hospital, and they begin to repair their relationship. They travel together to Sicily for Anthony's operatic debut. There, Michael asks Kay's forgiveness and says he had a different destiny planned for them; he regrets losing her and confesses he still loves her. Kay tearfully admits that she will always love him. Soon afterward, Michael retires as Don of the Corleone Family, naming his nephew Vincent (Andy Garcia) as his successor, and he and Kay reconcile. They attend Anthony's operatic debut, Cavalleria Rusticana, together in Palermo. After the performance, however, their daughter Mary is killed in an assassination attempt on Michael. Kay is last seen with Michael, sobbing over Mary's body.
Kay appears as a supporting character in The Godfather Returns (2004) and The Godfather's Revenge (2006), Mark Winegardner's two sequels to Puzo's original novel. The novels expand upon the early days of her relationship with Michael, her gradual estrangement from him, and her life after their divorce.