CIOK-FM (100.5 MHz) is a Canadian radio station in Saint John, New Brunswick, owned by the Maritime Broadcasting System.

CIOK-FM's switch to CHR joined sister station CKCW-FM in Moncton, which moved from top 40 to hot AC by that same time.

On December 3, 1986, Mervyn Russell, representing a company to be incorporated received approval from the CRTC to operate a new FM radio station at Saint John.

[1] The station began broadcasting in 1987 with Gary Crowell as the GM, and Jim Goldrich returned to CIOK from working at CJYQ in St. John's, Newfoundland and Labrador.

As of August 2011, MBS's website identifies CIOK-FM, and sister station CKCW-FM's, formats as being top 40 or CHR.