Brawn departed Mercedes at the end of 2013 but has been linked to several roles within the paddock, including as a replacement for Martin Whitmarsh at McLaren.
However at a fishing event in Scotland at the weekend, Brawn was adamant that his Formula 1 career has finished.
"What they didn't realise when I was invited here was they had a scoop because the world's press was trying to find out if I was retiring or not," Brawn is quoted in The Daily Telegraph.
"This is the busiest time of the year for Formula 1 and I said I would come along and open the River Dee.
"If they had put two and two together they would have realised I was definitely retiring. I'm retiring - it's not tongue in cheek."
"I'm going to take a year to enjoy the fishing and then see what life brings. I'm looking forward to it but I've got no other plans."
Brawn became a key ally of Michael Schumacher during the German's success in the sport, having teamed up at Benetton in 1994-5 and at Ferrari until 2006.
Brawn took a sabbatical and returned with Honda at the end of 2007 before subsequently leading his eponymous team to championship glory after Honda's departure in 2008.
He remained at Brackley following Mercedes's takeover of the team but left at the end of the season once a new management structure was in place.