Howe said: “After almost five years of pouring my life, heart and soul into this club with relentless energy, I believe the right move for both me and the club is to step aside, rest, and take a break.
“This has been an incredibly tough decision, but deep down I know it’s the correct one.
“Managing Newcastle United has been the greatest privilege of my life.”
Howe’s coaching team — Jason Tindall, Graeme Jones, Stephen Purches and Simon Weatherstone — will also depart St James’ Park, as will head of performance Dan Hodges.
He was appointed in November 2021 and guided the Magpies to 11th place that season.
In 2022-23 they secured Champions League qualification and did so again in 2024-25, while also lifting the League Cup.
Last season they reached the Champions League knockout rounds for the first time, falling to Barcelona in the last 16, but lost 17 of their 38 Premier League matches and missed out on European football for next year.
“We’ve shared so many incredible moments,” Howe added. “From battling relegation that first season to those unforgettable Champions League nights at St James’ Park soon after. The rise was rapid.
“Everyone pulled together, united, and we became a formidable force. I’ll cherish those memories forever.”
His final game at the helm was a 4-1 pre-season defeat to Bristol City at Ashton Gate on Wednesday.
This summer the Magpies have lost two key midfielders — Sandro Tonali to Tottenham and Anthony Gordon to Barcelona — while Arsenal are pursuing captain Bruno Guimaraes, who has made it clear he wants to join the Premier League champions.
Last summer, Newcastle spent roughly £240m on recruits, but Howe was left disappointed when the prolonged pursuit of Alexander Isak ended with the Sweden striker moving to Liverpool for a British-record £125m.
“I remain hugely optimistic and excited about the future of Newcastle,” said Howe.
“The club is in excellent hands with a strong leadership team and, together with whoever succeeds me, I’ve no doubt they will continue to bring success on the pitch.”
Newcastle’s chief executive David Hopkinson said: “Eddie and his staff leave with the profound gratitude and respect of everyone at Newcastle United, and with a lasting place in the club’s history.
“While we are naturally disappointed to see Eddie go, we are immensely thankful for everything he has done for the club.”