A doctor's son, Lester was educated at Denstone College, and worked in a variety of jobs (including at Dudley Zoo, in a pub, and as a civil service clerk), before he began his broadcasting career in 1977 for BBC local radio stations.
At Radio Tees, on joining, he narrowly avoided an attempt by Canadian programme controller Donald Cline to rechristen him "Red" Lester.
The meaningless but catchy show slogans are 'SCOF' (Swirling Cesspool of Filth) and 'Slap My Top' (thought to be a variation on the music hall phrase 'slap my thigh' – but reserved exclusively for people with bald heads) and listeners have marketed the show by writing the phrase in the dirt on the backs of trucks and vans.
Lester awarded these to people who came up with the most innovative uses of the slogan – winners included a local radio reporter who got the expression into a story; a man who wrote and recorded a song with the slogan as its title; a mystery girl, for placing an ad for Lester's show in the small ads section of a local newspaper and a man who developed a website which remains a communal meeting point for the programme's listeners, and is listed in the External Links section below.
As well as T-shirts, another listener produced a range of glow-in-the-dark Alex Lester wristbands, which were given away as prizes on the show.
For 16 years, starting in January 1994, the programme began at 3 am and finished at 6 am, until it was rescheduled in 2010 after changes to the Radio 2 morning schedule.
On 4 January 2019, Lester left the breakfast show on BBC Radio WM after nearly two years of broadcasting.
For nearly 10 years he lived aboard a 60-foot traditional stern canal boat (which he nicknamed The Blue Pig) during the week, while presenting his show from the BBC's Pebble Mill Studios and then The Mailbox in Birmingham.
Over the years Lester has participated in Extreme Downhill Cheese Rolling, the Yorkshire Celery Wrestling Finals and achieved a creditable 9th-place finish at the 2006 World Bog Snorkelling Championship.