Early career While playing football at the International Preparatory School in Lisbon, Dier's footballing ability was spotted by his
P.E. teacher Miguel Silva, who referred him to
Sporting CP for a trial at the age of eight. Dier signed professional terms with Sporting CP in April 2010. The Portuguese club beat
Arsenal,
Manchester United and
Tottenham Hotspur to his signature. Sporting CP also sold 50% economic rights of the player to a
third-party owner,
Quality Football Ireland Limited. In January 2011, Dier agreed to join
Everton on
loan until 30 June. Sporting CP's official website stated that the loan was "an opportunity for the athlete to grow in a more competitive and demanding environment". Dier represented
Everton U18s ten times during his loan spell and won the 2010–11
U18 Premier League with the team. Dier encountered difficulties resettling into English life, but in the summer of 2011, he extended his loan stay in the Everton academy for an additional 12 months.
Breakthrough at Sporting On 26 August 2012, Dier made his debut with
Sporting B in a
2012–13 Segunda Liga 3–1 away win against
Atlético, replacing
Diego Rubio in the 77th minute. On 4 November 2012, Dier scored his first senior goal with a
direct free kick against
Benfica B in a 3–1 away win in the
Segunda Liga. On 11 November 2012, Dier was called to play for the first team in a
Primeira Liga 1–0 home win against
Braga. Fifteen days later, he scored his first goal for Sporting CP's first squad in a 2–2 league away draw against
Moreirense.
Tottenham Hotspur in the
2015 League Cup Final On 2 August 2014, Dier signed a five-year contract with Tottenham Hotspur in a £4 million transfer. He made his competitive debut for the club on the first day of the
2014–15 Premier League season away to
West Ham United on 16 August, and scored the only goal of the match in added time. Eight days later, in his second match and in his
White Hart Lane debut, he
headed in a
corner from
Erik Lamela in an eventual 4–0 win over newly promoted
Queens Park Rangers. Dier started on 1 March 2015 as Tottenham lost the
2015 League Cup Final to
Chelsea at
Wembley. Dier signed a new contract on 9 September 2015, lasting until 2020. During the
2015–16 season, he was utilised as a defensive midfielder by Tottenham head coach
Mauricio Pochettino, On 15 August, he scored Tottenham's first goal of the
Premier League season in a 2–2 draw at home to
Stoke City, and on 26 September, Dier scored the team's equalising goal in a 4–1 home victory over
Manchester City. On 13 September 2016, Dier signed a new five-year contract to last until 2021. During the
2016–17 season, Dier returned to the centre-back position due to Tottenham's acquisition of defensive midfielder
Victor Wanyama and injuries to defenders
Toby Alderweireld and
Jan Vertonghen. On 25 October 2016, Dier
captained Tottenham for the first time in a 2–1 loss to
Liverpool at
Anfield in the fourth round of the
EFL Cup. He was also given the captain's armband for the 3rd and 4th round
FA Cup ties against
Aston Villa and
Wycombe Wanderers respectively. On 1 April 2017, Dier scored his first goal of 2016–17 in a 2–0 win over
Burnley in the
Premier League. In the
2018–19 season, Dier scored his first goal of the season, which is his first in 18 months, in the 1–0 win against
Cardiff City, helping Tottenham to their joint best start of a season in the Premier League after eight games. He underwent surgery mid-December 2018 due to
appendicitis, and returned to the team on 20 January 2019, coming on as a
substitute in the game against
Fulham. However, he continued to suffer the after-effects of the appendicitis operation, repeatedly falling ill and missing games. On 1 June, in Tottenham's first appearance in the
Champions League final, Dier replaced the injured
Moussa Sissoko for the final 16 minutes of a 2–0 loss to Liverpool in Madrid. He performed better in the
Champions League game against
Red Star Belgrade, helping the team to a 4–0 away win. On 4 March 2020, Dier was involved in a confrontation with a spectator in the stands following Tottenham's
FA Cup defeat by
Norwich City. Dier climbed into the lower tier at the
Tottenham Hotspur Stadium after the person "insulted" Dier and became involved in a dispute with Dier's brother Patrick who was also in the stand. The following day, the
Metropolitan Police said they wished to interview Dier, his brother and the supporter alleged to be involved in the incident. On 23 April, Dier was charged by the
FA with misconduct for a breach of FA Rule E3 due to his "improper and/or threatening" action. In July 2020, Dier was fined £40,000 and banned for four games. On 21 July 2020, Dier signed an improved contract until June 2024.
Bayern Munich On 11 January 2024, after a reduction in playing time under new Tottenham manager
Ange Postecoglou, Dier was loaned to
Bundesliga club
Bayern Munich on a six-month loan contract that would expire at the same time as his Tottenham contract in June 2024. However, the loan contract included the option for a one-year permanent contract with Bayern Munich should he achieve the required minimum number of appearances. Hence, he reunited with his former teammate
Harry Kane who had joined the club the previous summer. He made his debut for Bayern Munich on 24 January 2024 in a 1–0 win against
Union Berlin. On 1 March 2024, having made the requisite number of appearances to satisfy the clause in his loan contract, it was confirmed that Dier would permanently transfer to Bayern Munich at the conclusion of the season on an initial one-year deal. In the latter stages of the season, Dier formed a solid defensive partnership with
Matthijs de Ligt under coach
Thomas Tuchel, playing a crucial role in the club's progress in the
Champions League. On 16 April 2025, he scored his first goal for the club in a 2–2 away draw against
Inter Milan in the second leg of the
UEFA Champions League quarter-finals. Ten days later, he scored his first
Bundesliga goal in a 3–0 win against
1. FSV Mainz 05. On 10 May, Dier celebrated his first major career title as Bayern Munich clinched the Bundesliga championship with a 2–0 victory over
Borussia Mönchengladbach.
Monaco On 14 May 2025,
Ligue 1 club
Monaco announced the signing of Dier on a free transfer and a three-year deal, starting from 1 July. Later that year, on 16 August, he made his debut, scoring a goal in a 3–1 victory over
Le Havre. On 1 October, in the
league phase match against Manchester City in the
2025–26 UEFA Champions League, Dier earned a penalty which he converted from the spot in the final minute to draw the game 2–2. ==International career==