The 21-year-old, who joined the club in 2011, is a regular member of Arsenal head coach Arsene Wenger's starting line-up.
He signed a new long-term deal in July 2015 and has now been rewarded with another contract.
Speaking to Arsenal's official site, Bellerin said: "I'm really, really happy and this club is my home right now.
"I've been here for more than five years now so I was really, really excited when the club told me that they wanted to extend my contract.
"I wasn't thinking about anything else other than staying here and continuing my development here. This is where I'm happy. I'm just very grateful and pleased to have signed.
"Arsenal is not only about being a footballer, you have to be a good person to play here. That's what everyone transmits inside the club. You represent more than just a football club.
"I'm a player who tries to be an example for everyone, not just on the pitch but off it as well.
"Now I've just got to keep on progressing, keep working hard to be the best player I can be, and hopefully help the team to be where it's got to be, to win some silverware.
"That's what everyone wants and that's what I'm working towards."
FC Barcelona and Manchester City had reportedly expressed their interest over Bellerin.