If It's Tuesday, This Must Be Belgium is a 1969 American romantic comedy film made by Wolper Pictures and released by United Artists and made in DeLuxe Color. Directed by Mel Stuart, the movie was filmed on location throughout Europe, and featured cameo appearances. The film stars Suzanne Pleshette, Ian McShane, Mildred Natwick, Murray Hamilton, Sandy Baron, Michael Constantine, Norman Fell, Peggy Cass, Marty Ingels, Pamela Britton, and Reva Rose.

Suzanne Pleshette was an American actress. Pleshette was known for her roles in theatre, film, and television. She received nominations for three Emmy Awards and two Golden Globe Awards. For her role as Emily Hartley on the CBS sitcom The Bob Newhart Show (1972–1978) she received two nominations for the Primetime Emmy Award for Outstanding Lead Actress in a Comedy Series.