The Gunners have been wrestling their nearest rivals in recent weeks.
But it appears Saliba will be an Arsenal player rather than heading to Mauricio Pochettino’s side.
RMC journalist Mohamed Bouhafsi broke the news on Twitter this evening, writing that the deal will be announced on Tuesday.
“Arsenal and Saint Etienne have reached an agreement of around €29m bonuses included. On Tuesday, Saliba will commit to the gunners for five years,” he tweeted,
“Saliba’s willingness to join Arsenal influenced the negos. He will be loaned in the process #ASSE to! #RMCsport.”
Unai Emery were in the final stages of landing the 18-year-old before Tottenham trumped their offer earlier this month.
The respective lawyers of both parties were also putting the final touches on the contracts.
But Pochettino’s side then bid €30m (£26.8m) plus bonuses for Saliba’s signature, which goes well above Saint-Etienne’s valuation of the central defender.
The defender will be loaned back to Saint-Etienne for another season before joining the Emirates outfit next summer.
Emery hinted that a deal was close this week.
Speaking ahead of the win over Bayern Munich, the Arsenal boss said fans could expect more new arrivals in the near future.
“We are working, the club is working with the possibility to sign some new players to help us,” he said.
“We are doing a lot of meetings with the club, with (technical director) Edu, with Raul (Sanllehi, head of football) and also with Josh and Stan Kroenke on Monday in Denver.
“We have a clear idea to sign players to help us with quality and in the positions we need.
“We are taking with the patience and with the calm because we really want to sign players who can help us with a big performance and also because we think in the team we have very good players and young players and we also need to take the best player in some positions.
“Really, I can say to our supporters that we are going to have a very good team with the players that are there now and also with three or four players who can help us in a few days.
“Other players can come here to help us. We need, really, that they will come with a big performance and also our target is to achieve three or four players who really improve our team and our squad now.
“We are being very, very demanding and we are first speaking about the possibility to sign very big, very expensive players and the first player in our list is our first target. And after, if we cannot achieve that, then the second. But we are thinking every time that they are going to improve our squad.”