Financial details were not disclosed, but Argentine media reported the loan had a purchase option worth 11 million euros.
"I'm really happy to have joined this club. I'm coming here full of expectations, of getting to play and showing what I can do," Montiel said.
"I'm hungry to win things, to win trophies, now's the time to show this. I've been watching the Premier League since I was child. As a player, you want to play in the best league, and the Premier League is just that."
Montiel made 72 appearances for Sevilla, scoring two goals and providing six assists, since joining from River Plate in 2021.
He helped the LaLiga side win their seventh Europa League title last season by scoring the decisive penalty in the shootout to beat AS Roma in the final.
The right back, who has 23 caps for Argentina, also scored the last penalty to help his country beat France in last year's World Cup final.
