Fox premiered on October 9, 1986, consisting of three squares with the letters "FBC" which stand for the Fox Broadcasting Company.
On late 1986, it introduced a more familiar logo which based on the 20th Century Fox logo and the Fox wordmark was capitalized. It also featured the searchlights and the double pane platform under the name. The logo above used since April 5, 1987 is a print logo based on today's 20th Century Fox print logo. Until 1996, this logo still remained on some affiliates like KTTV. Rarely, this logo is still on some affiliates.
This logo was introduced on a pre-launch promo on very late 1986.
The current logo was introduced on September 1, 1993. Many different versions (some with and without the 20th Century Fox searchlights) were used over the years as seen below.