The 29-year-old, who is Arsenal's longest serving player would have seen his previous contract expire this summer.
Elneny joined Arsenal from FC Basel in January 2015 and has made 147 appearances in total for the club, scoring five goals and providing ten assists.
Elneny has not always been a regular starter in his time at Arsenal, spending time on loan at Besiktas in the 2019/2020 season.
The Egypt international was again consigned to the fringes for much of the 2021/2022 season but showed his worth in Thomas Partey's absence, impressing and featuring in Arsenal's last seven league matches of the season.
“Midfielder Mohamed [Elneny] is extending his stay with us,” Arsenal revealed on their official website. “Elneny has been a key member of the squad since joining us from Basel in 2016. He's made 147 appearances, scoring five goals and contributing 10 assists.”
Arsenal manager Mikel Arteta explained his decision to keep the player: “Elneny is a really important part of the team,” Arteta said. “He brings endless energy, enthusiasm, and commitment to the team and is loved by everyone.
“He's an important player for us on and off the pitch, a real role model to our younger players and I'm delighted he's staying."
“I feel like when you play in one of the biggest teams in the world and you have an amazing family and the fans are really amazing as well - they make me feel special,” Elneny told the same portal.
“You feel like you are special for this club and this club is special for you. Of course, I want to stay here until I finish my career actually.”