WSDK signed on October 6, 1963 as WEXT, licensed to West Hartford, Connecticut, with a 1000-watt daytime-only signal on 1550 kHz and a country and western format. The studios at that time were located at 999 Farmington Avenue in West Hartford Center and the transmitter and tower were at 99 Grassmere Avenue in West Hartford. Flood control work on Trout Brook adjacent to the transmitting tower resulted in damage to the ground system.

In 1972, the studios were moved to the 2nd floor of the Culbro Building at 630 Oakwood Avenue in West Hartford.

In 1977, the station changed ownership and the call letters were changed to WMLB, which was a combination of the first names of the three owners: Mary, Lou and Barry. Soon afterward, WMLB was one of the first stations in the state to install a satellite downlink when the Mutual Broadcasting System, of which WMLB was an affiliate, agreed to place a 3 meter downlink on the roof of the transmitter building. This site then served as the Connecticut hub for Mutual and also for the Associated Press for the next ten years.

In 1985, the station was sold to a group of investors from Long Island, New York, and the format became talk radio as The Talk of Hartford. Springfield talk show host Dan York was brought in as Program Director and the station secured the rights to run The Larry King Show at midnight, formerly on WPOP. Shortly afterward, the station's city of license was changed from West Hartford to Bloomfield, Connecticut, and the transmitter site was moved to Bloomfield to facilitate a daytime power increase up to 5,000 watts and the addition of nighttime service at 2,400 watts. The Bloomfield facility, which is still in use today, utilizes six tower on 9 acres (36,000 m2) of land in its directional antenna system. It also changed its call letters to WGAB the following March. However, the talk format proved short lived: by the end of the year, WGAB went off the air due to financial hardship, and the station remained silent for nearly two years.

In September 1988, the station returned to the air as WLVX under the ownership of Living Communications, who also owned WLIX in Islip, New York. The new owners brought a Contemporary Christian format to the station and they moved the studios to the Wintonbury Mall in Bloomfield.

In 1993, the station was sold again, this time to a local group who changed the call letters to WRDM and began programming station in Italian. The studios were moved to 880 Maple Avenue in Hartford where they shared space with a sister low-power television station, W13BF (which subsequently changed its call letters to WRDM-LP to match the radio station).

In 1998, the station was sold again, this time to Hibernia Corporation. The format was switched to Radio Disney and the studios moved to Franklin Avenue in Hartford. The call sign was changed to WDZK.

The Walt Disney Company purchased the station from Hibernia in 2000 and continued to operate from the Franklin Avenue location until 2004 when the studios were moved to 160 Chapel Road in Manchester, Connecticut. In February 2008 WDZK commenced HD Radio broadcasting.