Trewan from Rhineland-Palatinate craft black metal steeped in the Celtic and Germanic heritage of their western German homeland since 2021. Their name hints at old-world roots, channeled through atmospheric extremity from the Rhine Valley.

Tribes of the Moon from Rennes craft black metal channeling lunar-aligned tribal mysticism through atmospheric compositions since 2018. Their pagan-inflected name drives ritualistic extremity from the Breton capital.

A Viennese black metal band founded in 1993, Trifixion were part of the founding nucleus of the Austrian Black Metal Syndicate alongside Abigor, Golden Dawn, Pazuzu, and Summoning — whose original 1993 lineup included Trifixion's Alexander Trondl on drums and vocals. After contributing to Summoning's early demos and their 1995 debut "Lugburz," Trondl departed to pursue electronic music under the Vienna Subs project.

Trijumf are a Bosnian black metal band whose 2024 debut album Trijumf ili Smrt – Trijumf, released on Death Prayer Records, directly confronts the history of the Bosnian War. The record's four extended tracks — including '1425 dana,' referencing the 1,425-day siege of Sarajevo — combine raw, melodic black metal with an overtly pagan and patriotic sensibility.

Avant-garde black/death metal band from Plovdiv, Bulgaria—a city whose ancient Roman name, Trimontium, the band has adopted. Their 2021 demo, a four-track release, introduced their unconventional approach to extreme metal that blends black and death metal structures with more experimental and dissonant elements. Operating out of Bulgaria's second-largest city and former European Capital of Culture, they occupy a distinctive niche in the country's underground.

Trinacria emerged in 2005 from a collaboration between Ivar Bjørnson of Enslaved and noise artists Maja S.K. Ratkje and Hild Sofie Tafjord of Fe-mail, originally commissioned by Rikskonsertene as a concert piece. The project merges Norwegian black metal architecture with avant-garde noise composition and free improvisation, placing it at an unusual intersection of extreme metal and the contemporary classical underground. Their debut full-length Travel Now Journey Infinitely documents this volatile synthesis.

Trinakria is a black metal band from Syracuse, Sicily, formed in 2019. Named after the ancient Greek name for Sicily, their music channels the island's deep mythological heritage through raw black metal.

Triptykon was formed in Zürich, Switzerland in 2008 by Thomas Gabriel Fischer following the dissolution of Celtic Frost, his second celebrated band after Hellhammer. The project continues Fischer's exploration of extreme, gothic, and doom-inflected metal across two studio albums, Eparistera Daimones (2010) and Melana Chasmata (2014), both on Century Media. Dense, funereal, and deliberately paced, Triptykon represents Fischer's most introspective and stylistically unified work to date.

Triskele is a black metal band from Ayr, Scotland, active since 2003. Named after the ancient triple spiral symbol, their music channels Celtic mysticism and darkness through over two decades of black metal from the Ayrshire coast.