Dyke started life as a DJ at Shanklin Youth Club in January 1975 at the age of 12. At 16, Dyke had managed to gain work at several night clubs on the Isle of Wight even though he was legally too young.
By the early 1980s, Dyke was working at some big clubs in the South with some of the top chart stars of the day. He presented numerous showbiz interviews at Portsmouth's local commercial radio station Radio Victory before joining BBC Radio Solent in early 1984 to help out on their youth show Something Else.
In 1985, Dyke joined Radio Luxembourg at their Mayfair studios in London taking control of future programme ideas and recording specials and documentaries. In 1986, Dyke moved closer to home to start work at a new station, Ocean Sound where he fronted late nights, afternoons and Drive Time until 1991. During the 1980s and 1990s he also presented shows for Northsound Radio in Scotland, Nova The Power FM and Contact 94 in France.
In 1990, as part of the ITV Telethon whilst at Ocean Sound, Dyke broadcast a 27-hour non-stop radio show from the TVS television studios in Southampton and was featured many times in the TV coverage for this event. In 1991, he joined Isle of Wight Radio to present the Midmorning show and in 1992 introduced the daily phone-in which he presented for the next 17 years.
By the year 2000, the daily phone-in had become "must listen radio" with 30% of the calls coming from the UK mainland. However, despite having his midmorning show networked to sister station The Quay in Portsmouth, co-presenting the late night radio show North South Divided with Mike Elliott ("Mike The Mouth") across all 28 radio stations in The Local Radio Company and winning Sony awards for Isle of Wight Radio, in December 2008 he was fired. After living in the United States for a year in 2009 and presenting programmes in Orlando for News radio 1190am and ESPN 1080am, Dyke returned to the UK to work for BBC Radio Solent.
Dyke now presents the Midmorning show Monday - Friday and Bubblegum and Cheese on Saturday 11am - 2pm.
Artists such as Mud, Slade, Showaddywaddy, David Cassidy, Donny Osmond, The Monkees and The Hollies are often featured on the radio show Bubblegum and Cheese. It began in 2005 when Dyke was asked to present an extra show at weekends. The programme quickly went from being broadcast on just one radio station to 20 stations in The Local Radio Company network. In 2010 Bubblegum and Cheese moved to the BBC and can be heard on BBC Radio Solent every Saturday from 11am. In 2011, Dyke took Bubblegum and Cheese on the road, and now tours with artists and plays at various large-scale events across the country.
Dyke is credited with inventing the Row Boat Dance that goes with the Gap Band 1980 disco hit "Oops Up Side Your Head." He recalled "It was early summer 1980 I was 18 at the time and my uncle had just returned from a trip to New York, he was always buying me stuff, this time he came back with a bunch of 12" disco singles for me. The Gap Band song was the one I really liked because it was so weird but I remember thinking that it sounded that it would be a little hard to dance to for my regular crowd as the beat was very different to the dance hits of the day from acts like The Whispers, Gene Chandler, Chic, Sister Sledge and Edwin Starr. I was DJ ing at a couple of clubs at the time Keats Inn at Shanklin and Col Bogeys in Sandown. The first time I played it was on a hot early Summer night. I was itching to get it on the turn table but was worried that as a brand new song and unfamiliar to crowd it could clear the floor. We had had some kind of a regatta that day on the Island where they had played games on the beach for the kids, all sorts of funny silly games. One was a rowing game. I remember putting this song on and telling the dancers to "hit the deck and row the boat home" a couple of girls got it straight away and sat down and started to row. I shouted over the mic that you should "join in - join in" and that was that. From that moment on I played it every night and people hit the floor. At the time there were about 25-30 clubs on the Isle Of Wight and other DJ's started copying straight away."
Within weeks the craze first seen at the Colonel Bogeys discotheque in Sandown had spread to London and across the country. Even Elton John was talking about it on the BBC show Top of the Pops.
He added "I remember someone telling me that Elton had mentioned it on Top of the Pops and I couldn't believe it. Not many of us had video recorders at the time so I just had to take their word for it. I never dreamed that the dance would stick with people for all these years, I just assumed that when the song dropped out of the charts that the dance would disappear also."
Dyke presented a short series for ITV Meridian called People Power and has guested several times on ITV's The Time and the Place. He presented an American Chart Show for the now defunct Solent TV who also used to film his daily lunchtime phone-in which he hosted for Isle of Wight Radio. The phone-in received cult status when picked up by a Sky TV channel. Martin Lee at London's LBC Radio said "It's car crash radio on train crash TV."
On 13 August 2015, Dyke made comments on BBC Radio concerning his dislike of breastfeeding in public, calling it "unnatural" and stating that it "must be stopped". These comments prompted his suspension from the BBC. Alex Dyke was reinstated to BBC Radio Solent on 20 August 2015.