Humphrey Bogart was a last minute replacement for Cary Grant. Bogart and William Holden couldn't stand each other. Bogart disapproved of Audrey Hepburn (he wanted his wife Lauren Bacall in the role), while Holden fell in love with her. Bogart got $300000, Holden got $150000, and Hepburn only $15000. Asked how he liked working with Hepburn, Bogart replied: "It's OK, if you don't mind to make 20 takes."
Although Edith Head won an Oscar for costume design, most of Audrey Hepburn's wardrobe was by Hubert de Givenchy. In fact, Hepburn chose her own clothes to wear from de Givenchy's collection. This was her first time working with the French designer, and he would become her costumer of choice for most of her career.
This was the second film in a row where Audrey Hepburn gets her hair cut as a symbol of maturity. The first was in Roman Holiday (1953). It is also the first of four films in a row where she'd play a character romantically linked with a man old enough to be her father.
Like Sunset Blvd. (1950), this film started production without a finished script. Ernest Lehman worked himself to exhaustion working on the script with Billy Wilder during production. One day, when Lehman did not have an extra copy of a scene rewrite to give to Humphrey Bogart, Bogart exploded. Wilder told his crew they would not film another foot of film until Bogart apologized to Lehman. Bogart invited Lehman to his dressing room and shooting eventually continued.
The original title of "Sabrina Fair" was reinstated in the UK due to well known TV personality, Sabrina (real name Norma Sykes) who became an icon simply by appearing on The Arthur Askey Show (1961). Askey, at little over 5 feet tall got huge laughs just by standing next to the statuesque Sabrina, whose substantial bosom became her trade mark, never spoke any lines. The film distributors thought the momentary stardom of the Rubenesque Sabrina in the UK would mislead British audiences.