The club and its new owners, a Saudi Arabian-led consortium fronted by co-owner Amanda Staveley and new chairman Yasir Al-Rumayyan, have been searching for a new manager since sacking Steve Bruce over a fortnight ago.
On Monday, 43-year-old Howe was announced as the new Toon boss in his first job since leaving Bournemouth in August 2020.
He told the club website: “It is a great honour to become head coach of a club with the stature and history of Newcastle United. It is a very proud day for me and my family.
“This is a wonderful opportunity, but there is also a lot of work ahead of us and I am eager to get onto the training ground to start working with the players.
“I would like to thank the club’s owners for this opportunity and thank the club’s supporters for the incredible welcome they have already given me. I am very excited to begin our journey together.”
Howe led Bournemouth from League Two to the Premier League in two stints as the Cherries manager that spanned over 450 games. He managed Burnley for 18 months in between those spells but struggled at Turf Moor while seeking promotion from the Championship.
Newcastle are sat 19th in the table after a 1-1 draw at Brighton on Saturday, which left them as the only club in the league yet to win a game. The club had sought Villarreal’s former Arsenal manager Unai Emery last week, before he committed his future to the LaLiga club.
Co-owner Staveley added: “We have been incredibly impressed by Eddie through what has been a rigorous recruitment process.
“As well as his obvious achievements with AFC Bournemouth, where he had a transformational impact, he is a passionate and dynamic coach who has clear ideas about taking this team and club forward.
“He is a great fit for what we are trying to build here. We are delighted to welcome Eddie and his staff to St. James’ Park and very much look forward to working together towards our collective ambitions.”