BOB fm was an Independent Local Radio station broadcasting to north Hertfordshire in the United Kingdom.

Launched as Hertbeat FM in 2001, it was subsumed into Heart Hertfordshire on 31 May 2019 shortly after acquisition by media group Communicorp.

The station proposed "an imaginative, music-led service, targeted at discerning 25 to 54-year olds, with intelligent speech that emphasises local news and information.

[8] The station continued offering locally oriented content, music and request shows using a roster of presenters through the day and night.

[12][13][14] Unlike HertBeat, Jack FM rejected listener's requests, a stance reinforced by the brand slogan, "Playing what we want".

In November 2013, as the Jack FM period drew to a close Steve Folland departed the station, replaced by industry veteran Graham Mack.

On 31 May 2019, the final live presented show, "BOB's Breakfast" with Brett Harley and Chris Hubbard ended with "Are You with Me" by Lost Frequencies.

BOB fm ceased broadcasting at 4pm, handing over to Heart Hertfordshire for the station's drivetime show from Watford.

Chris Hubbard won "Newsreader of the Year" at the Independent Radio News (IRN) Awards, having previously been twice shortlisted.