The Scot will line up alongside Cook at the Brackley squad, formerly known as BTC Racing, in Honda Civic Type R machinery.
Cook and Moffat will form a two-car attack under the banner of Starline Racing by One Motorsport, in deference to new title backing from Starline, a division of aftermarket giant LKQ Euro Car Parts.
Moffat, 26, has raced since 2019 with his own family team under the name of Laser Tools Racing. For 2020 and 2021 this merged with BMR Racing and carried Ash Sutton to the BTCC title in each of those years with the Infiniti Q50.
Since joining BTC for the 2019 season, Cook has scored 16 race wins and has been a regular in the top echelons of the overall championship, with a best position of third in the standings in 2021.
One Motorsport team principal Danny Buxton told Autosport: “It was important for us to make sure that we have competition for Josh in the team, another driver capable of delivering race victories.
“If you look at 2021, Aiden proved that he’s capable of winning and in the right hands under us I think we can turn him into a championship contender. He’ll be working together with Josh.
“With Josh, we led the [overall] championship for half the season last year and things went a little south for various reasons, but if we can take the lessons from that into the new campaign then this has got to be the year [to challenge for the overall title].
“In my opinion, Josh drives at a world-class level, and having Aiden to push him will make things even better.”
Moffat added: “Seeing how competitive they were in the Honda Civic FK8 gives me a massive buzz that I just didn’t have last year.
“Despite spending so much time in the BTCC, this is the most comfortable I have felt going into a season.
“Racing is a bit like business – you want to deal with the right people and that’s what we now have for this year with One Motorsport.”
The exit of Moffat’s team from the BTCC frees up the two TBL entrants’ licences in his possession.
Buxton confirmed to Autosport that One Motorsport is hoping to use one of these to expand its overall line-up from three Hondas to four.
Jason Plato and Jade Edwards teamed up alongside Cook in 2022. Rumours of BTCC legend Plato reversing his decision to walk away from the series as a driver refuse to dissipate, while Edwards is also understood to be working on a deal for 2023.
BTCC line-up so far
Motorbase Performance Ford Ash Sutton, Dan Cammish, TBA, TBA
West Surrey Racing BMW Jake Hill, Colin Turkington, Adam Morgan, Stephen Jelley
Excelr8 Motorsport Hyundai Tom Ingram, Tom Chilton, Ronan Pearson, Nick Halstead
Team Dynamics Honda TBA, TBA
One Motorsport Honda Josh Cook, Aiden Moffat, TBA, TBA
Speedworks Motorsport Toyota TBA, TBA, TBA
Team Hard Cupra Dan Lloyd, Bobby Thompson, Dexter Patterson, TBA, TBA
Power Maxed Racing Vauxhall Andrew Watson, TBA
