Sunderland appointed David Moyes as their new manager on Saturday, replacing Sam Allardyce who has taken charge of the England team.
The 53-year-old Moyes, who has been without a club since being sacked by Spanish side Real Sociedad in November, has signed a four-year contract at the Stadium of Light, the Premier League club said in a statement.
"I am delighted to have joined Sunderland. I am relishing the challenge and excited by the opportunity," Moyes told Sunderland's website.
"I have taken over a big British club, with a great support and I'm looking forward to working in the Premier League again.
"I look forward to continuing the good work done by Sam."
The Scot's last managerial job in England was his ill-fated spell in charge of Manchester United in 2013-14, following Alex Ferguson's retirement.
He has also managed Preston North End, with whom he won the Second Division title, and Everton, where he spent more than 11 years.
Under Allardyce Sunderland narrowly avoided relegation last season, finishing fourth from the bottom in the 20-team league.
"We are absolutely delighted to welcome David Moyes to Sunderland, who was by far and away our first choice," Sunderland chairman Ellis Short said.
"He is a man whose football pedigree speaks for itself and is someone I have long admired."
"He was my number one managerial target for the last five appointments, but his desire to honour existing contracts meant we were not able to bring him to Sunderland previously."
"To be able to finally welcome him as our manager is fantastic news for the club."