Xavi Simons expressed his excitement about joining the club, saying, "I'm really happy and can't wait to get going. I've been dreaming of this for a long time."
He added, "It's a great club, and when I met the head coach, I knew straight away that this was the right place for me. I will bring flair to the team, but also hard work and discipline. I want to do everything I can to win, for the team and also for the fans."
Tottenham had been keen to sign Simons, having missed out on other targets. Chelsea held talks with the player earlier in the transfer window but never made an official bid.
Spurs boss Thomas Frank is pleased with the signing, saying, "I'm really pleased we have brought Xavi in - he is a great addition to the squad. He is still young, but he already has good experience and has played a lot of games at the top level."
Xavi Simons came through the Barcelona academy and had spells with Paris Saint-Germain and PSV Eindhoven before joining RB Leipzig. He has made 78 appearances for Leipzig, scoring 22 goals and providing 24 assists.
In his international career, Simons has netted five times in 28 appearances for the Netherlands. He joins Mohammed Kudus, Joao Palhinha, and Kota Takai as Tottenham's new arrivals this summer.