It was a substantial but not spectacular box-office success, taking $3.7 million on its initial U.S. release. Initial critical reaction was generally positive, but some reviews were less enthusiastic: The New Yorker rated it only "pretty tolerable".
At the 1943 Academy Awards, the film won three awards: Best Adapted Screenplay, Best Director, and Best Picture.
The script, based on the unproduced play "Everybody Comes to Rick's" was purchased from authors Murray Burnett and Joan Alison by Warner Brothers for $20,000.
There has been anecdotal evidence that Casablanca may have made a deeper impression among film-lovers than within the professional movie-making establishment. In the November/December 1982 issue of American Film, Chuck Ross claimed that he retyped the screenplay to Casablanca, only changing the title back to "Everybody Comes to Rick's" and the name of the piano player to Dooley Wilson, and submitted it to 217 agencies. Eighty-five of them read it; of those, thirty-eight rejected it outright, thirty-three generally recognized it (but only eight specifically as Casablanca), three declared it commercially viable, and one suggested turning it into a novel.
By 1977, Casablanca was the most frequently broadcast film on American television.