It ends a long period of huge uncertainty at Everton, a nine-time English champion which has been an ever-present in the top division since 1954 but is without a major trophy since 1995.
Fronted by Dan Friedkin and his son Ryan, the group has investments in the automotive industry, entertainment, hospitality and sports. The Friedkins made a fortune distributing Toyotas in Texas.
They take over from Everton's majority shareholder, Farhad Moshiri, who has been at the club since 2016 but hasn't brought any success despite spending hundreds of millions of pounds on players.
"I take immense pride in welcoming one of England's most historic football clubs to our global family," Dan Friedkin said. "Everton represents a proud legacy, and we are honored to become custodians of this great institution.
Everton are 16th in the 20-team league and could be facing another fight to avoid a costly relegation from the world's most lucrative soccer league.
There may be some concern among Everton fans about the Friedkins, who have never spoken publicly in the four years since they purchased Roma and are unpopular with supporters after making contentious management changes — including firing Daniele De Rossi, the club's beloved former captain, this season.
However, the sale will at least remove Everton from the Moshiri era, which promised so much but ultimately failed to deliver.
The club has been hemorrhaging money in recent years as Moshiri desperately sought a buyer, with the team leaving its long-term home of Goodison Park at the end of this season and moving into a new, state-of-the-art stadium at Bramley-Moore Dock that is close to completion.
The new owners said they had six goals, including "strengthening the men's first-team squad through thoughtful and strategic investment" and "enhancing Everton's reputation as a unique and historical name in world football."