Tomlinson was born in Blytheville, Arkansas and raised in Kennett, Missouri. His father is a former basketball star who set scoring records at the University of Missouri and was drafted by the Cleveland Cavaliers. He was also the basketball coach, biology teacher, and assistant principal at Kennett High School.
In his junior year of high school, Tomlinson reached the finals for "You Can Be a Star", a television talent show on The Nashville Network (now Spike TV), in which Trent placed second. After numerous deals cut short due to labels that went bankrupt or were being taken over, Tomlinson landed a songwriting deal with Cal IV Entertainment. Some of his songs were recorded by Emerson Drive and Blue County on their respective debut albums. He also cut some sides for Lyric Street Records, with whom he later signed a record deal. Tomlinson's debut single, "Drunker Than Me", was released in late 2005, followed by his album Country Is My Rock. Two additional singles were also released from the album: "One Wing in the Fire” (a song about Trent’s father) and "Just Might Have Her Radio On."
Tomlinson also co-wrote "Missing Missouri" on Sara Evans' album Real Fine Place, "Why Can't I Leave Her Alone" on George Strait's album It Just Comes Natural, “Close Your Eyes” by Parmalee, and the 2018 BMI Country Song of the Year “In Case You Didn’t Know” by Brett Young.