WQGN-FM (105.5 MHz "Q105") is a commercial radio station licensed to Groton, Connecticut, and serving the New London–Groton area.

It broadcasts a contemporary hit radio format and is owned by Cumulus Media.

The "SUB" in the stations' call signs stood for "submarine", because shipbuilding is a major industry in the area.

At first, WSUB-FM simulcast the Middle of the Road (MOR) programming heard on the AM station.

The station started with the TM studios syndicated stereo rock format.