Undercurrent is a 1946 American film noir drama directed by Vincente Minnelli and starring Katharine Hepburn, Robert Taylor, and Robert Mitchum. The screenplay was written by Edward Chodorov, based on the story "You Were There'" by Thelma Strabel, and allegedly contained uncredited contributions from Marguerite Roberts.

Katharine Houghton Hepburn was an American actress whose career as a Hollywood leading lady spanned six decades. She was known for her headstrong independence, spirited personality, and outspokenness, cultivating a screen persona that matched this public image, and regularly playing strong-willed, sophisticated women. She worked in a varied range of genres, from screwball comedy to literary drama, which earned her various accolades, including four Academy Awards for Best Actress—a record for any performer.