The 30-year-old is expected to complete the move before Tuesday's 23:00 BST transfer deadline, with a medical at Everton still to come. Grealish had attracted interest from several clubs, including boyhood side Aston Villa, but opted to head back to Merseyside.
The Manchester City player spent much of last season with Everton on loan, making 20 appearances and contributing two goals and six assists. His campaign was cut short in January when he suffered a foot injury that ruled him out for the remainder of the season.
Grealish has made just two appearances for City this term. He featured as a substitute in their Community Shield defeat against Arsenal before again coming off the bench during the Premier League victory over Bournemouth. He was unused in Friday's 4-1 win over Crystal Palace.
Grealish joined City from Villa in August 2021 for 100m pounds, but is now poised to temporarily leave the club once again.
Everton are also working on several other deals as they look to improve their attacking options. They have agreed to pay Lyon £3m for versatile Englishman Ainsley Maitland-Niles, who can operate at full-back or in midfield and has five England caps.
The Toffees appear close to landing Monaco and USA forward Folarin Balogun in a deal worth around £40m. Meanwhile, winger Iliman Ndiaye is expected to move in the opposite direction, with Manchester City reportedly set to pay 65m pounds for the 26-year-old.
Everton's efforts to bring Richarlison back from Tottenham have, however, stalled over personal terms.
