In June 1918, Fitzgerald was garrisoned with the 45th and 67th Infantry Regiments at Camp Sheridan near Montgomery, Alabama. Attempting to rebound from his rejection by Ginevra, a lonely Fitzgerald began dating a variety of young Montgomery women. At a country club, Fitzgerald met Zelda Sayre, a 17-year-old Southern belle and the affluent granddaughter of a Confederate senator whose extended family owned the first White House of the Confederacy  Zelda was one of the most celebrated debutantes of Montgomery's exclusive country club set. A romance soon blossomed,  although he continued writing Ginevra, asking in vain if there was any chance of resuming their former relationship.

Three days after Ginevra married a wealthy Chicago businessman, Fitzgerald professed his affections for Zelda in September 1918. Fitzgerald's Montgomery sojourn was interrupted briefly in November 1918 when he was transferred northward to Camp Mills, Long Island.  While stationed there, the Allied Powers signed an armistice with Germany, and the war ended. Dispatched back to the base near Montgomery to await discharge, he renewed his pursuit of Zelda Together, Scott and Zelda engaged in what he later described as sexual recklessness, and by December 1918, they had consummated their relationship. Although Fitzgerald did not initially intend to marry Zelda,  the couple gradually viewed themselves as informally engaged, although Zelda declined to marry him until he proved financially successful.

After his daughter's birth, Fitzgerald returned to drafting The Beautiful and Damned. The novel's plot follows a young artist and his wife who become dissipated and bankrupt while partying in New York City. He modeled the characters of Anthony Patch on himself and Gloria Patch on—in his words—the chill-mindedness and selfishness of Zelda. Metropolitan Magazine serialized the manuscript in late 1921, and Scribner's published the book in March 1922. Scribner's prepared an initial print run of 20,000 copies. It sold well enough to warrant additional print runs reaching 50,000 copies. That year, Fitzgerald released an anthology of eleven stories entitled Tales of the Jazz Age. He had written all but two of the stories before 1920. 

Following Fitzgerald's adaptation of his story "The Vegetable" into a play, in October 1922, he and Zelda moved to Great Neck, Long Island, to be near Broadway.  Although he hoped The Vegetable would inaugurate a lucrative career as a playwright, the play's November 1923 premiere was an unmitigated disaster.The bored audience walked out during the second act. Fitzgerald wished to halt the show and disavow the production.  During an intermission, Fitzgerald asked lead actor Ernest Truex if he planned to finish the performance.  When Truex replied in the affirmative, Fitzgerald fled to the nearest bar.  Mired in debt by the play's failure, Fitzgerald wrote short stories to restore his finances. Fitzgerald viewed his stories as worthless except for "Winter Dreams", which he described as his first attempt at the Gatsby idea.  When not writing, Fitzgerald and his wife continued to socialize and drink at Long Island parties.