Bay FM was originally licensed as part of a Commonwealth Government plan to increase the diversity of radio services in regional centres.
The station’s launch date is disputed – the Australian Communications and Media Authority, which oversees licensing of radio services in Australia, list the station’s launch date as 10 December 1989, however some listeners suggest that broadcasts began two days earlier on 8 December.
Just before the official launch of the station, the parent company of Bay FM purchased the flagging 3XY in nearby Melbourne, from the then owners of 2SM Sydney.
Once Bay FM commenced broadcasting, 3XY briefly simulcasted the station overnight, retaining its soft rock format during the day. However, once new studios in Corio Bay were completed, Bay FM and 3XY began full-time simulcasting, 3XY breaking only for coverage of AFLAustralian Football League games.
After a period of 12 months, the then-Australian Broadcasting Authority demanded the two stations begin separate programming. While the two stations remained in their Corio studios, Bay FM relaunched with an easy listening format. In 1991, 3XY was sold to AWA Limited, owners of 2CH Sydney and other stations, who immediately shut the station down and re-opened it later that year as 3EE.
Bay FM was purchased by Grant Broadcasters, owners of rival 95.5 K-Rock, and the station relocated to the K-Rock building in the center of Geelong. In 1999, Bay FM adopted the adult contemporary format it broadcasts today. In December 2015 the station changed its on-air name from “BayFM” to “bay93.9” looking to a future when broadcasting in the digital DAB+ format and following the trend of stations to drop reference to the “FM”.