Newcastle United have signed England defender Kieran Trippier from Atletico Madrid for £12m plus add-ons.
The 31-year-old is Newcastle’s first signing since a Saudi Arabian-backed takeover was completed in October.
“I’m delighted to be joining this fantastic club,” said Trippier, who has agreed a deal until the end of the 2023-24 season.
Eddie Howe, appointed Newcastle manager in November, also signed Trippier in 2012 during his time as Burnley boss.
Trippier said: “I really enjoyed my time in Madrid, but when I became aware of interest from Newcastle United, and having worked with Eddie Howe before, I knew this was where I wanted to be.”
Trippier, who won the Spanish title with Atletico last season, had 18 months left on his contract.
Newcastle are second bottom of the Premier League, having won one league game this season.
“I’m aware there is a lot of work ahead of us but I know the demands of Premier League well and I know what an amazing club this is with very talented players,” said Trippier, who joined Atletico in 2019 after four years at Tottenham.
“I can’t wait to get started and I’m excited to step out at St James’ Park as a Newcastle player.”
Howe said he had “long admired” Trippier, adding: “When the opportunity arose to secure him, we didn’t hesitate.
“A lot of hard work has gone into planning for the January transfer window long before the month began, which is clear in how quickly we have been able to complete this move.”
Trippier, who was part of the Spurs side that reached the Champions League final in 2019, made 83 appearances for Atletico following his £20m move.
He made his England debut in 2017 and was part of the squad that reached the semi-finals of the 2018 World Cup and the final of European Championship last summer.
Newcastle host Cambridge United in the FA Cup third round on Saturday and fellow strugglers Watford in the Premier League on 15 January.
‘There will be more activity at Newcastle’ – analysis
Alistair Magowan, BBC Sport
Newcastle fans will be feeling a little bit happier with the world.
Not only does it represent good value for an England international who won La Liga last season, but underlines that the new Saudi Arabian-backed owners mean business in this transfer window.
In many ways they need to be, given the club’s position in the Premier League table. Yet Trippier’s switch has shown that, despite Newcastle’s form, the allure of playing for Eddie Howe at a club with a new direction could encourage other players to join him on Tyneside.
This is good early business but there will be more activity before the end of January. Howe, head of recruitment Steve Nickson and consultant Nicky Hammond have been working hard in preparation for further moves. They want to strengthen in central defence and midfield, as well as find a striker after the recent calf injury to top scorer Callum Wilson.
Find all the latest football transfers on our dedicated page.