Tuomas Seppälä is a Finnish guitarist, keyboardist, and composer, best known as a founding member and main composer of the Finnish symphonic power metal band Amberian Dawn.^[1]

Seppälä started playing piano at the age of five, and in his teen years he got interested in 1980s rock, pop and heavy metal, including Ritchie Blackmore, Ronnie James Dio, Yngwie Malmsteen and ABBA.^[2] Seppälä joined the band Virtuocity as a keyboardist in the early 2000s (decade), and when the band disbanded in 2005 he formed a new band called Atheme One with Tommi Kuri and Peter James Goodman, led by his songwriting skills. In 2006, he and Tommi Kuri decided that they wanted to transform the band to include female vocals, but the same compositional style, and found the classical soprano Heidi Parviainen, with whom they formed what would be Amberian Dawn.

Seppälä graduated at Helsinki University of Technology in 2000.