Mac Tonight was McDonald's 1986 advertising character who sang about the moon.
The campaign featured a character with a crescent-moon head, dark sunglasses, and a tuxedo. Mac Tonight sang a parody of Bobby Darin's 1959 song “Mack the Knife,” changing the central idea to “Mac Tonight” and emphasizing evening dining.
The advertisements were created to promote McDonald's as a place for dinner rather than only a daytime stop. The character became especially associated with the song, piano playing, and a stylized nighttime atmosphere.
Mac Tonight is often confused with a permanent McDonald's mascot such as Ronald McDonald. It was primarily a promotional advertising character, and the campaign was later withdrawn after a copyright dispute involving Darin's estate. Its imagery nevertheless remains a notable episode in McDonald's branding history.