Bortoleto won the F3 title at the first attempt in an impressive 2023 campaign with Trident, winning twice and scoring consistently throughout the season to shade Williams protege Zak O'Sullivan by 45 points.
The Brazilian was announced as a member of McLaren's Driver Development Programme in October and will now graduate to F2 as it ushers in a new Dallara chassis that replaces the previous model introduced in 2018.
"We’re delighted to have Gabriel Bortoleto joining us for his debut season in Formula 2," said team principal Andy Roche.
"His consistency throughout his rookie campaign in Formula 3 impressed everyone and earned him a convincing and thoroughly deserved championship victory. This was acknowledged by the world of F1 as he became a McLaren Development Driver.
"Gabriel has visited us at our base in Norfolk and kept in touch since his signing.
"He’s left a good impression on everyone here and has quickly become part of the team.
"We were impressed by his adaptation to Formula 3 and, like everyone, are excited to see what he can do in 2024 as he continues to hone and add to his already admirable skillset."
Bortoleto said that "our goal will be to aim for the best positions for the team" and aspires to "build a strong and consistent story with them throughout the year".
“We will have a new car in the championship, and our first challenge will be to adapt quickly and efficiently to start the year on a high note," the 19-year-old said.
"I am coming from a season of significant personal growth, culminating in the FIA F3 title.
"I hope to continue this process of evolution as a driver in 2024 and naturally become a victorious driver in the next stages of my career."
Bortoleto will be joined at the Norfolk squad by Alpine Academy driver Maini, who has been working with double world champion Mika Hakkinen as part of his management team.
The 23-year-old Indian driver moves across from Campos after a rookie season that yielded a single podium finish in Melbourne and 11th in the standings.
"Kush has had a solid debut season in Formula 2," added Roche.
"He got up to speed immediately and was able to produce good results in 2023. We’ve already spent considerable time with Kush since he first signed for the team and his mentality and approach align well with ours.
"He has shown dedication and an impressive work effort, and we look forward to helping him add to his F2 podium tally as he continues to improve as a racing driver."
Maini said: "They have a great pedigree in Formula 2 and, prior to that, in GP2, and I am looking forward to growing further as a racing driver with the team.
"I’ll do my best to hopefully bring many trophies back to the workshop."
Virtuosi won the final round of the 2023 season in Abu Dhabi on Sunday, with Jack Doohan scooping his third feature race victory on his way to finishing third in the standings behind Theo Pourchaire and Frederik Vesti.
The team finished second in the teams' standings in 2019, 2020 and 2021, while Callum Ilott finished runner-up in the drivers' championship in 2020.