The 22-year-old centre-back was into the final 12 months of his contract, with Arsenal eager to make him commit his long-term future as soon as possible.
Saliba became a crucial first-team star under Mikel Arteta last season, having signed for the north Londoners for £27million in 2019.
The Gunners have now successfully tied down the talented French international until 2027, according to a report by The Athletic’s David Ornstein.
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His new contract is understood to be worth a staggering £10m-per-year. It does not include a release clause nor an option to extend.
Saliba becomes the latest of three young first-team stars to pen new deals, following Gabriel Martinelli and Bukayo Saka’s own extensions until 2027.
It marks a hugely productive summer thus far for Arteta and sporting director Edu in making the Gunners a force for the future, having also signed new players in Kai Havertz, Declan Rice and Jurrien Timber.
And the Arsenal faithful were left ecstatic on social media, tweeting: “We’re winning the treble,” and “We’re f***ing massive!!!!”
A third tweeted: “What a summer for Arsenal,” while a fourth added: “what a time to be an Arsenal fan.”
Saliba’s breakthrough 2022/23 season saw him make 27 league appearances. His ability on the ball and assuredness at the back quickly made him a fan favourite as well as an irreplaceable asset to Arteta.
The Frenchman missed the last 11 games of the season to injury in what is considered to be the main reason the Gunners lost their eight-point lead in the Premier League title race, before finishing as runners-up to Manchester City.
Yet the Parisian has had to be patient when it comes to his success in a red and white shirt.
He was sent back to Ligue 1 on loan three seasons in a row after his transfer, initially to original club Saint-Etienne, followed by Nice and Marseille.
Fans feared the worst when Saliba was sent out on his third spell to Marseille ahead of the 2021/22 campaign, with Ben White taking his number-four jersey. Yet the defender returned to the Emirates a more polished player, having grabbed Ligue 1’s Player of the Year award.