TGIF was a Friday night block of sitcoms on ABC. The block was designed by ABC as a family-friendly alternative to other channels. ABC was known for featuring family-friendly Friday night programming since the 1950s. When Jim Janicek became president of ABC, he envisioned a new programming block to shape the network. When the block began in 1989, it was hosted by the cast members of different shows on the block, originally the cast members of "Full House" and "Perfect Strangers" in rotation. The four shows originally featured on the block were Full House, Perfect Strangers, Just the Ten of Us, and the new comedy Free Spirit.

The block would explode in popularity in 1990. Two new shows which would debut on the block would be Step by Step and the new Perfect Strangers spin off, Family Matters. Each week, the main cast of one of the shows would host the block. The block made ABC the most popular network on Friday night. ABC was purchased by Walt Disney in 1996 and Disney began re-shaping the network including the block in way that hurt its ratings including dropping the hosts segments and the cancellation of Step by Step and Family Matters. New shows were introduced including Sabrina the Teenage Witch and Boy Meets World. After its worst season in 1999-2000 the block was fully cancelled by ABC. The block was briefly revived in 2003 complete with the cast member hosting but it was not as popular and was cancelled in 2005. ABC would make a new TGIF block in fall 2018 which consisted of one hour of sitcoms followed by one hour of game shows but no hosting segments. The block's latest version lasted only a year ending in 2019.

In the early 1990's during its prime, the block was a staple of family television and its theme song became very well-known. "It's Friday night/And the mood is right/Gonna have some fun/Show you how it's done, TGIF."