WREX (channel 13) is a television station in Rockford, Illinois, United States, affiliated with NBC.

It shared ABC with NBC affiliate WTVO, channel 17 (which signed on five months earlier), and also aired programming from the DuMont Television Network.

Rex Caster was a First Lieutenant in the United States Army who was killed in France during World War II.

In 1963, the station was sold to the Gannett Company; during the mid-1960s, WREX was briefly co-owned with the Rockford Morning Star.

In 1969, Gannett sold WREX to the Gilmore Broadcasting Corporation, owner of WEHT in Evansville, Indiana.

[7] However, on April 29, Gray announced that WREX would be divested to Allen Media Group in a $380 million deal that includes, among other Quincy-owned stations, WKOW, WXOW in La Crosse, and WQOW in Eau Claire.

WREX began to air newscasts in high-definition on December 12, 2010, the second in the Rockford market after WIFR and the third in the Quincy Newspapers station group after KWWL and WKOW.

Subchannels 13.4 and 13.5 went on the air with color bars on April 30, 2019, with Justice Network launching on 13.5 on May 1, and Court TV on 13.4 a week later.