The 19-year-old, who made three appearances for the first team during the 2016-17 season, is now tied to the Cottagers until 2020.
The San Diego-born midfielder made his debut in August 2016 during a 3-2 victory over Leyton Orient in the EFL Cup.
After signing his contract extension, De la Torre told the club's official website: "It's a great feeling. I've been at this club for a few years now and it definitely feels like home for me.
"There are a lot of opportunities for me this year to play well for both Fulham and the USA, and I'm looking forward to grabbing the opportunity with both hands.
"I was a bit unlucky at the beginning of the season, I was injured during pre-season and I've been out since but now I'm back in training so hopefully it's onwards and upwards from here."
The United States Under-20 international has been part of Fulham since 2013.