Trivium cross multiple heavy metal genres such as metalcore, thrash metal, progressive metal, alternative metal, groove metal, and death metal. Their style has evolved over the years from their earliest work on Ember to Inferno right through to Shogun, there is a clear thrash influence from Metallica and Machine Head, as well as some early In Flames. Trivium has stated that in general they are influenced by musical groups such as Metallica, In Flames, Machine Head, and Iron Maiden.
Upon the release of their second album Ascendancy, Trivium were identified as metalcore with strong elements of thrash metal, with the third track on the album “Pull Harder on the Strings of Your Martyr” becoming a permanent fixture in the band's set lists and the rest of the album selling itself to gold status. Ascendancy was even featured as one of Metal Hammer’s Albums of the Decade. Later releases have marked changes in the band. The Crusade was seen as a major shift in musical direction due to the change in vocal style, namely the absence of screaming, and some of the melodies featured.
The Crusade is a much more thrash-oriented album and lyrical content was also different in direction, citing current affairs, such as the Yates murders and the 1999 Amadou Diallo killing. In Autumn 2008, Trivium released Shogun, which has a heavy Japanese influence on its title track as well as the first single release "Kirisute Gomen", which translates to "authorization to cut and leave". Acknowledging Matt Heafy’s Japanese heritage,the album also was described more favorably as more their own style, as previous references to Trivium sounding like Metallica had been made on the back of The Crusade.The Crusade made sparing use of 7-string guitars, which were featured heavily on Shogun.
Many of the songs on Shogun draw lyrical inspiration from Greek mythology. "Into the Mouth of Hell We March" and "Torn Between Scylla and Charybdis" detail the story of Odysseus choosing whether to face the giant whirlpool Charybdis or the 6-headed monster Scylla. "He Who Spawned the Furies" is about the Titan Cronos devouring his children and castrating his father Uranus, creating Aphrodite and the Erinýes (the Furies). "Of Prometheus and the Crucifix" references the daily torment of Prometheus and alludes to crucifixion of Jesus Christ, serving as a metaphor for enduring torment by the public for daring to contribute something new to society. "Like Callisto to a Star in Heaven" is written from the perspective of the nymph Callisto, detailing her rape and impregnation by Zeus and her transformations into a bear and into Ursa Major. "Down from the Sky" features a contemporary theme, chastising those who spark wars for profit or religion, and warning of nuclear holocaust.