Jena is a southern metal band from Brescia in northern Italy, formed in 2013 and describing themselves as a southern metal band from northern Italy. After nearly dissolving in 2018, they reconstituted with a new lineup and have since released Graboid (2021) and Outlaw (2023), delivering groove-heavy, riff-driven southern metal.

JJax is the solo project of Julien Jacquemond from Chambery, France, a veteran of several metal bands including Inner Visions, Further Dimension, and Dead Season. His solo work channels his decades of experience as a vocalist, composer, and multi-instrumentalist into original metal compositions with strong melodic hooks.

Jointhugger is a Norwegian heavy psychedelic doom rock band active since 2012, self-described as hashtronauts of the heavy playing cosmic, psychosonic doom rock straight from the fjords. Their trilogy of albums including Surrounded By Vultures (2021), composed by Nico Munkvold and recorded live at Stone Bone Cross Studio, channels deep fuzz and occult heaviness.

Jumping Jack is a French stoner rock trio from Nantes, delivering organic melodies built on a heavy rock wall since their debut Cows and Whisky (2009). They gained international exposure through a 25-date European tour in 2013 and have shared stages with Orange Goblin, Nashville Pussy, and Mustasch across three albums.

Jurassic Leaf is an instrumental doom/sludge/stoner metal band from Lille, France, whose album Groovosaur (2016) delivers six tracks of crushing, groove-oriented instrumental metal. Their prehistoric-themed compositions have earned praise as an instrumental juggernaut of captivating, eye-melting chugs.

Jager Blaster is a post-stoner rock trio from Besancon, France, blending psychedelic, doom, and stoner influences across three albums since 2014. Their most recent release Introspecta (2019) features nearly 50 minutes of heavy, intense psychedelic stoner rock with immersive atmospherics.