Matthew Lee (born 1 October 1985), known professionally by his stage name Gammer, is an English music producer and DJ.

Gammer first appeared in the hardcore scene in 2002 and has since released songs under the Essential Platinum label.

Gammer has often released on the label Monstercat, where he's released tracks such as "Party Don't Stop", "Over the Edge", and an extended play, The Drop, whose title track[9][10] became one of the most played festival dubstep songs of 2018 with eleven official remixes.

[11] Gammer has collaborated with fellow producer Kayzo for multiple songs including "Forever" and "Over the Edge", the latter of which was released on 11 August 2018.

In 2021, Gammer began releasing singles from his upcoming debut full-length album through Dim Mak Records, including "Stampede" with Fatman Scoop, "NGMF" with Riot Ten, and "Replay the Night" with Staysick and Nytrix.