Maloney joins the Italian outfit, which won its first ever F3 silverware last season, from Formula Regional European Championship by Alpine - where he finished fourth for R-ace GP.
Trident's trio of Jack Doohan, Clement Novalak and David Schumacher helped the Milanese squad beat Prema to the teams' honours, as Doohan battled with Dennis Hauger for last year's championship.
With Doohan and Novalak stepping up to F2, Maloney comes in to partner Red Bull junior and Aston Martin Autosport BRDC Award nominee Jonny Edgar, who moved across from Carlin.
Maloney will hence become the first Barbadian driver to drive in FIA F3.
"I am proud to debut in the FIA Formula 3 Championship with Trident Motorsport, the queen among the teams in the series." said Maloney.
"Throughout the last season, I think I have grown as a driver, both in terms of managing the race weekends and in paying attention to every detail.
"Together with Trident Motorsport, I want to continue in this direction, and I am sure that there are all the ingredients to do well in the FIA Formula 3 Championship.
"I can't wait to get out on track and start this new adventure in an extremely popular and competitive series".
After winning the British F4 title in 2019, Maloney remained with Carlin for a tilt at the Euroformula Open championship, finishing eighth overall before moving to FRECA.
Maloney's signing leaves just one seat available at Trident for 2022, while Prema is currently the only team with a complete line-up - with German and Italian F4 champion Ollie Bearman joining second-year drivers Arthur Leclerc and Jak Crawford.
ART also has one seat to fill, having signed FRECA champion Gregoire Saucy and retaining the services of Juan Manuel Correa.
Alexander Smolyar was announced on Thursday as MP Motorsport's first announced driver for 2022, while Red Bull junior Isack Hadjar has joined Hitech for his first season in the category.
Charouz, Campos, Jenzer, Carlin and newcomers Van Amersfoort Racing are yet to announce any driver signings.
