The 27-year-old had two years remaining on his initial deal with speculation linking the defender with a move to Spanish side Atletico Madrid.
Those rumours have now been put to bed as the Argentina international signed with the London outfit until 2029.
The new contract comes just five days after new manager Thomas Frank appointed Romero as Spurs' captain following the departure of Heung-Min Son to MLS side LAFC.
Romero originally joined Tottenham on loan from Serie A side Atalanta in August 2021 before making the move permanent the following year.
He has made a total of 126 appearances for Spurs to date, scoring eight times, while also being part of the team that lifted the Europa League trophy last season.
Romero made his senior debut for Argentina in a World Cup qualifier against Chile in June 2021, and has so far racked up 44 caps while scoring three times.
The defender played a crucial role in helping Argentina win Copa America titles in 2021 and 2024 and, most notably, the World Cup trophy in 2022.
Tottenham Hotspur have ramped up their pursuit of Crystal Palace's Eberechi Eze, with sources indicating they are on the verge of submitting a formal bid for the versatile midfielder.
In a thrilling UEFA Super Cup clash in Udine, Paris Saint-Germain overcame a 2-0 deficit to defeat Tottenham Hotspur 4-3 on penalties after a 2-2 draw, claiming their first Super Cup title and fifth trophy of 2025.
Yves Bissouma has been left out of the Tottenham squad to face Paris Saint-Germain in the UEFA Super Cup on Wednesday night.
Bayern Munich are reportedly preparing to part ways with star striker Harry Kane in the summer of 2026, sparking intense speculation about a potential Premier League comeback.
