Iranian businessman Farhad Moshiri has bought a 49.9% stake in Everton, the Goodison Park club says.
Moshiri, 60, sold his stake in Arsenal to business partner Alisher Usmanov on Friday so he could buy into Everton, who play Chelsea in the FA Cup quarter-finals next month.
"After an exhaustive search, I believe we have found the perfect partner to take the club forward," Everton chairman Bill Kenwright said.
The deal needs Premier League approval.
"I have got to know Farhad well over the last 18 months," Kenwright added. "His football knowledge, financial wherewithal and true blue spirit have convinced me he is the right man."
Providing there are no problems, it will bring to an end Everton's decade-long search for new investment.
Kenwright, who bought Everton from Peter Johnson for £20m on 26 December 1999, said he was prepared to sell as far back as November 2007.
After years of inertia regarding a sale, there has been a growing intent to do a deal in recent months, fuelled by serious interest from a number of parties.
Kenwright has also been suffering from poor health and has rarely attended Everton games this season.
"Bill Kenwright has taught me what it means to be an Evertonian," Moshiri said.
"There has never been a more level playing field in the Premier League than now."
