The deal will be made official when the international transfer window opens. The Toffees are allowing the French midfielder to train with his new club in the meantime.
Nice director of football Julien Fournier said Tuesday that Schneiderlin's transfer fee will be between €2 million and €4 million.
"We believe we have a very young and talented squad. But it needs more consistency, more character. Thanks to his experience, Morgan offers us that," Fournier told French radio station Europe 1. "We made a similar transfer a few years ago in the form of Dante. We have done it again with Morgan, for a very reasonable transfer fee."
Schneiderlin will join Nice after they finished in fifth place following the early cancelation of the 2019-20 French campaign. The 30-year-old started 12 Premier League matches for Everton this season and had one year remaining on his contract.