The England youth international s made 33 first-team appearances for Arsenal so far this season
The 18-year-old, who came through the club’s academy, has made a great impact during this season after making his debut in the Europa League in last year.
Saka tweeted: “London is my home. Arsenal my team. I’m so happy to finally announce my contract extension. “I love playing for this club and I’m looking forward to what the future holds. The hard work continues so I can continue living my dream.”