Niklas Sundin (born 13 August 1974) is a Swedish musician, best known as a founding member and former lead guitarist of the melodic death metal band Dark Tranquillity from 1989–2020.

In 2019, he founded his own band called Mitochondrial Sun, which has released two full-length studio albums to date.

[2][3][4] He is also a member of Time and the Hunter, a project founded in collaboration with Italian musician Enrico Longhin.

Sundin is also the founder of Cabin Fever Media, which among other things creates artwork for metal bands.

He previously used Rocktron Chameleon rack mounted pre-amplifiers, but after the Damage Done tour, he and Martin Henriksson began using Peavey 5150 and Mesa/Boogie Dual Rectifier amplifiers along with Behringer V-AMP 2 modeling processors.