The 31-year-old right-back is the first signing of the PIF ownership era as he joins for a reported £12million fee plus add-ons.
Signing a La Liga winner and England international will be seen as a big coup for Newcastle, who currently sit 19th in the Premier League table.
Trippier has enjoyed an impressive career in England, Spain and at international level and will be looking to make a mark on Tyneside to help The Magpies keep their top flight status intact.
He will wear the number 15 shirt for Newcastle and could be part of the squad that faces Cambridge United in the FA Cup third round at St James’s Park on Saturday (3pm kick-off).
Following Trippier’s arrival at Newcastle, we’ve looked at his career so far and picked out 10 key moments, some of which have have helped him establish himself as one of world football’s best right-backs.
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5. 2013-14 Championship title win with Burnley
Trippier played a key role in Burnley's promotion to the Premier League in the 2013-14 season. He played 41 times in the Championship for The Clarets that season, registering one goal and an impressive 12 assists from right-back. His performances saw him named in the Championship team of the season for the second time. Photo: Jan Kruger
6. Making a mark at Spurs
Trippier signed for Tottenham Hotspur from Burnley in 2015 and initially found first team chances hard to come by with Kyle Walker hard to displace at right-back. But after Walker joined Manchester City, Trippier was given a regular chance in the side under Mauricio Pochettino. His form for Spurs saw him called up to the England squad for the first time in 2017. He went on to establish himself as one of the best full-backs in the Premier League and scored directly from a free-kick in his first start of the 2018-19 season against Fulham at Wembley Stadium. Photo: Julian Finney
7. World Cup 2018
Trippier was a breakout star in his first major competition for England back in 2018. His crossing ability helped The Three Lions get to the semi-finals of the competition in Russia where the defender enjoyed his highlight moment by curling a free-kick into the top right corner of the goal to give England an early lead in the match. England went on to lose the game 2-1 after extra time but the goal remains Trippier's only strike for his country. His performances in the World Cup also saw him named in the official team of the tournament. Photo: Alexander Hassenstein
8. Champions League final 2019
Trippier's final appearance for Tottenham Hotspur came in the 2019 UEFA Champions League final against Liverpool. Spurs lost the match 2-0 but Trippier played a key role in helping the North London club reach the final with a crucial assist for Fernando Llorente in the second leg of their quarter final match against Manchester City. The goal saw Spurs advance on the away goals rule. Photo: OSCAR DEL POZO