TGIF is the abbreviation for the phrase Thank God (or Goodness) It's Friday. Commonly used in American conversation, it has become a common element for advertising and promotional materials, to connote a sense of partying and the weekend, such as:

• The restaurant chain TGI Friday's.
• The Florida resort Web site TGIF, for Thank God It's Florida.
• Cadbury's Crunchie chocolate bar ran a commercial of which the slogan was "Thank Crunchie it's Friday". The commercials were followed by more, most of them connecting Crunchie with Fridays.
• The slogan of a programming block on the ABC TV network. See: TGIF (ABC)
• The name of a 1978 Movie Starring Donna Summer