If It's Tuesday, This Must Be Belgium is a 1969 romantic comedy film made by Wolper Pictures and released by United Artists. It was directed by Mel Stuart and produced by Stan Margulies with David L. Wolper as executive producer. The screenplay was by David Shaw, the music score by Walter Scharf and the cinematography by Vilis Lapenieks.

The film stars Ian McShane, Suzanne Pleshette, Mildred Natwick, Murray Hamilton, Michael Constantine, Sandy Baron, and Norman Fell. It also has cameo appearances by Patricia Routledge, Marina Berti, Senta Berger, John Cassavetes, Joan Collins, Vittorio De Sica, Anita Ekberg, Ben Gazzara, Virna Lisi, Elsa Martinelli, Catherine Spaak, Robert Vaughn and Luke Halpin. Folk singer Donovan makes a guest appearance in the film singing Lord of the Reedy River, which he had also written. He also wrote the title song for the film, but he didn't sing it as it was performed by J.P. Rags. The then current Miss Belgium, Sonya Doumen, also appears.

The title, also used by a 1965 blank">documentary on CBS television that filmed one such tour, was taken from a magazine cartoon caption*, humorously depicting the whirlwind nature of European tour schedules, which formed the premise of the film's plot. Director Mel Stuart is best-known for _Willy Wonka and the Chocolate Factory (1971).

A group of travelers from the United States race through seven countries in 18 days. Included in the group are Suzanne Pleshette as a lovely young miss who finds time for some romance with handsome Britisher Ian McShane; Mildred Natwick as an elderly lady with energy to spare; Norman Fell and Riva Rose as a married couple who get separated; and Sandy Baron as an Italian-American who almost gets married off while visiting relatives in Venice. Written by filmfactsman