The 1941 screwball comedy starring Barbara Stanwyck and Henry Fonda that features a con artist is The Lady Eve.
Preston Sturges wrote and directed the film, which follows Jean Harrington, a clever confidence woman played by Stanwyck. She and her father target Charles Pike, a wealthy, socially awkward heir played by Fonda, aboard an ocean liner. Jean unexpectedly falls in love with her intended victim, complicating the planned swindle.
The film is based on a story by Monckton Hoffe and combines romantic comedy, deception, class satire, and physical humor. After Charles discovers Jean's scheme and rejects her, she reappears under the invented identity of Lady Eve Sidwich, turning the con into an elaborate attempt to win him back.
A common mix-up is with Bringing Up Baby, another celebrated 1930s screwball comedy involving an eccentric romance, or with Ball of Fire, which also stars Stanwyck. The Lady Eve was selected for preservation in the U.S. National Film Registry in 1994.