Matthew Jean Paul Walst (born December 28, 1982) is a Canadian musician who is the co-lead singer and rhythm guitarist of the rock band Three Days Grace, which also includes his older brother Brad as bassist.

[10] Following Adam Gontier's departure from Three Days Grace in January 2013, Matt Walst was brought on as their replacement lead vocalist for their tour and was later made the permanent lead singer of the band.

[16] In 2024, Three Days Grace announced that Gontier had officially rejoined the band and that Walst would also remain as a singer.

[17] Walst joined Bighead, Yung Booke and Young Thug on the single, "Emotions", in 2021.

In 2022, Walst was inducted into the Norwood District High School Hall of Honor along with his brother Brad and then-former vocalist Adam Gontier.