The striker has risen through the youth ranks in North London and enjoyed a prolific 2020-21 season with 25 goals and four assists from 24 appearances at Under-18 and Under-23 level.
The 18-year-old has been rewarded with fleeting appearances in the first team over the past couple of years, but he is yet to establish himself as a fully-fledged member of Antonio Conte's senior crop.
Scarlett has made a total of 10 appearances for Tottenham so far - providing one assist in Europa League action against Wolfsberger in February 2021 - but he is still waiting for his first goal.
The 2021-22 season saw Scarlett made seven appearances at senior level during an injury-hit campaign, with his only Premier League outing coming off the bench away to Leeds United.
"I'm really proud and excited to see what the future holds. It's something I've been working towards this year and now it's happened, I'm just happy to be here and still enjoying my football," Scarlett told tottenhamhotspur.com after signing his new deal.
"I think it's amazing that I have this opportunity to work with these kinds of people. I've obviously got a bit bigger and stronger [since my debut] and mentally stronger. I understand what it takes to break through into the first team.
"The training sessions that he [Antonio Conte] does is very beneficial to the attacking players. It's good to be around and understand the way he plays. The opportunities keep coming and I'm trying to keep taking them.
"The first team is definitely a big step but it's something that I wanted to do. Training makes you good in games so if I keep training hard and working hard so I'll be able to do well when I get my opportunity on the pitch.
"Hopefully I'll get more opportunities to play, it means everything to me. This is something I've been working towards my whole life so to be in this position now is just amazing."
At international level, Scarlett has scored 10 goals from as many appearances for England's Under-19 side, including six goals from five European Championship Qualifying matches earlier this year.