The station was launched in 1955 by Rideau Broadcasting, at 1070 AM, and played a country music format. In 1958, the station's frequency changed to 630.
In 1969, CJET-FM was also launched as a stereo simulcast of the AM signal. That station now uses the callsign CKBY.
In 1984, the AM and FM stations were sold to Harvey Glatt'sCHEZ-FM Inc., which was subsequently acquired by Rogers Media, the stations' current owner, in 1999. Rogers converted CJET to FM the following year, and the station adopted the Jack FM branding in 2004. CJET is the one of the only Jack FM stations in the US or Canada to not have an adult hits format.