Tranqvillitas Maris specialize in the glacial extremes of funeral doom metal, stretching compositions into vast expanses of grief-laden slowness from their base in Luxembourg. Since 2016, the project's name — Latin for 'Sea of Tranquility' — has reflected the cosmic desolation embedded in their monolithic sound.

Transcendent Barrier is a doom/sludge/stoner metal band from Hamminkeln, Germany, formed in 2019. They deliver crushing, multi-layered doom with sludge and stoner metal influences.

Transfiguration is a funeral doom metal band from Banagher, Ireland, formed in 2019. They create glacially paced, crushingly heavy funeral doom with extended compositions and overwhelming atmosphere.

Transhumance is a Swiss instrumental doom duo of Jo Transhume and Manu Le Bé, crafting crushing riff-driven compositions without vocals across releases like "Blood Therapy" and their self-titled "II." Their sound pairs monolithic doom heaviness with a tongue-in-cheek Swiss identity, citing raclette and wine alongside depression as creative fuel.

Transparent Lust is a death/doom metal band from Macerata/Urbania in the Marche region, formed in 2023. Their evocative name channels desire through the dark filter of death and doom metal.

Traps of Doom from Greece craft doom metal and ambient that ensnare the listener in inescapable heaviness since 2016. A decade of trap-setting compositions has produced music that holds fast and refuses to release.

Treeshadow is a doom/stoner/sludge metal band from Madrid, Spain, formed in 2022. They combine doom, stoner, and sludge into a crushing wall of heaviness.

Treitum is a doom metal band from Barcelona, Spain, formed in 2012. They deliver crushing, deliberate doom metal from the Catalan capital.

Tilburg's Treurwilg — Dutch for 'weeping willow' — craft melodic doom/death metal that lives up to their arboreal name's mournful connotations since 2015. Their music pairs crushing heaviness with sorrowful melody, rooted in the city's thriving underground heavy music community.