The 20-year old, who represented his country at this summer’s Toulon Tournament, has signed a 5-year deal at White Hart Lane.
Born in England, Dier moved to Portugal at a young age and was swiftly snapped up by Sporting. He progressed through the ranks at Academia Sporting and remained in Lisbon when his parents returned to England in 2010.
In 2011, Dier enjoyed a six-month loan spell at Everton, although he did not represent the first-team. The following season represented his breakthrough at Sporting – having made his debut for the B-team in August, he was subsequently promoted to the first-team just a few months later. Dier went on to make 30 first-team appearances in Portugal, scoring once.
He has represented England at U18, U19, U20 and U21 level.