The move sees him split with his partner of more than ten years, Clive Pickering, who remains at TBWA. The pair's repertoire includes the highly decorated Volkswagen "wedding" press ad, as well as Johnnie Walker's "fish".
At O&M, Dawson will work alongside Dennis Lewis and the recently appointed Rich-ard Russell, in the position of creative partner. Dawson will take responsibility for the agency's global BP and Castrol accounts. The agency is looking to recruit a fourth creative partner to oversee its Ford output.
O&M's executive creative director, Malcolm Poynton, said: "Neil has a terrific track record across all kinds of local and international brands in both press and TV. He is a team player who works closely with his peers and clients to produce great work.
"Neil's joining will complement the line-up of creative partners and I'm sure his influence on our work will be very apparent."
At TBWA, Pickering and Dawson worked on the Absolut, Cunard, Martell and Eurostar accounts. They joined in 2001 from Bartle Bogle Hegarty.
Before BBH, they spent five years at BMP DDB.
Dawson, who started his advertising career as a junior art director at Leo Burnett, said: "It was a tough decision to leave TBWA and Clive but I felt I needed to do something on my own."