The 21-year-old Portugal international midfielder joins from West Ham United.
Mateus said: "I'm very excited for this next step. Spurs is a massive club and the Head Coach was a key part of why I have decided to join.
"When we spoke, it was very special. We look at football in the same way - going onto the pitch as a strong team, with fight and energy, to try and win every game. I can't wait to get started, to meet the fans, to meet everyone, and give everything for the Club."
Sporting Director, Johan Lange, said: "I'm delighted to welcome Mateus to the Club.
"He is a player with outstanding technical ability, intelligence and maturity, and even at a young age, has shown he can perform consistently in demanding, high-pressure environments. We believe this is the right place for Mateus to take the next step in his career, working with our outstanding coaching staff and alongside an ambitious and talented group of players.
"I know our supporters will enjoy watching him, as he has the talent, mentality and work ethic to become a very important player both for the present and the future of Tottenham Hotspur."
Head Coach, Roberto De Zerbi, said: "I've admired Mateus for a long time because he combines quality on the ball with the intensity and intelligence that are so important in the way we want to play.
"Despite his age, he already has good experience in the Premier League and has shown quality and consistency at this level. Mateus is comfortable under pressure, can progress the ball, works hard for the team and has the courage to make things happen in difficult moments. I believe this is the ideal environment for him to continue his development and I'm excited to start working with him."
One of the outstanding young players in Europe, Mateus has gained valuable Premier League experience over the past two seasons after first impressing at Southampton and then with West Ham last term.
A product of Sporting CP’s illustrious academy, he moved there from local club Olhanense in 2016 and progressed through the ranks over the next eight years at the Lisbon-based club.
Featuring regularly for Sporting’s B team in the third tier at 17 years old in 2021/22, the following campaign saw him make his first team debut in the Primeira Liga in October, 2022, and, four days later, came off the bench at Tottenham Hotspur Stadium for his maiden UEFA Champions League appearance in our 1-1 draw in the group stage.
Ending with seven first-team appearances across the board that term – including a UEFA Europa League knockout game against Midtjylland – the tireless midfielder was loaned out to Portuguese top-flight side Estoril in 2023/24, featuring 28 times in the league and helping them reach their first cup final in 80 years.
Departing Sporting for Southampton at the age of 20, Mateus ranked in the top 10 for duels won (208) across his 36 appearances in the Premier League and produced six goal contributions (two goals, four assists) - including a stoppage-time strike in their 3-1 defeat in N17 – in 2024/25.
A constant presence in midfield throughout his maiden season in England, he stood out to claim Southampton's Player of the Season award before joining West Ham at the end of August, 2025.
Mateus made his Hammers debut two days after signing and was ever-present in the Premier League from that point onwards, adding another 36 appearances to his tally.
With a strong defensive work-rate and ball-carrying ability, the all-round midfielder was a standout performer as he finished joint-fifth for most tackles (103) in the league and chipped in with three goals and four assists last term. He also won West Ham’s Goal of the Season award for his superb long-range attempt in a home win over Sunderland in January.
Representing Portugal at every age group from Under-18s through to the Under-21s, his excellent form at club level earned him a call-up to the senior squad in March, 2026, and made his first and only cap to date as a late substitute in a 2-0 win over the USA on 1 April.
Welcome, Mateus!