Tomiyasu has played 73 games in all competitions for the Gunners since joining from Bologna in 2021.

"Together with his natural ability and strength, Tomi's attitude, mentality and values are first-class," said manager Mikel Arteta.

"Tomi is loved by everyone and has been an integral part of the squad since joining us.

"The way he trains, with his desire and determination to be the best version of himself every day, is admirable."

Tomiyasu, who can play across the back four, has made 20 appearances for Arsenal in all competitions this season, scoring his first goal in a 5-0 Premier League win over Sheffield United in October.

Arsenal are top of the Premier League on goal difference with 10 games remaining as they seek a first title since 2004.

They face Bayern Munich in the Champions League quarter-finals next month.