Karevik was born in 1981 in Botkyrka, Sweden. He began singing at a young age, and was a member of his elementary school’s choir.

In 2004, Tommy Karevik recorded a few songs with Vindictiv. Shortly after, he left the band for progressive metal band Seventh Wonder, prior to the release of their debut album Become in 2005. Despite the warm reception of the album at the time of its release, the band members have stated that they were generally unhappy with the album due to its poor mixing. Once Karevik joined the band, they toured briefly to promote the album.

The band then returned to the studio, eager to produce fresh material with their new vocalist. The resulting album was Waiting in the Wings, released in 2006. The album was met with very positive reviews.

In 2008, Seventh Wonder released the concept album Mercy Falls, and in 2010 they released The Great Escape.

In 2011, Karevik performed as a guest vocalist for the American symphonic metal band Kamelot. Kamelot was forced to tour without their longtime vocalist Roy Khan, who was unable to perform due to personal problems and health issues. Khan was replaced on tour by Italian singer Fabio Lione of Rhapsody of Fire and during the tour Kamelot announced that Khan had left the band. During Kamelot’s tour of Europe, Karevik joined the crew, singing mostly backing vocals, but also performing solo on the songs EdenEcho and Center of the Universe.

After Karevik was announced as the new vocalist for Kamelot in 2012, the band only reunited in 2013 to play shows at some festivals and to announce they would be recording a live DVD at 2014 ProgPower USA Festival, performing songs from their album Mercy Falls in its entirety.

On June 22, 2012, Kamelot announced that Karevik had joined as lead singer, replacing Roy Khan.

On August 31, 2013, Karevik was announced as a guest vocalist, playing the lead role, in the progressive rock opera project Ayreon’s album The Theory of Everything. On December 15, 2016, Karevik was announced as “The Opposition Leader” on Ayreon’s release, The Source released in 2017. He was presented by Arjen Lucassen as “one of the best singers in the world right now… “

In 2016, the band signed with Italian record company Frontiers Records to release the live CD/DVD called Welcome To Atlanta Live 2014 on September 23, 2016 and also a new studio album to be released in 2018. Later, the band announced the album would be titled Tiara. It was released on October 12, 2018.

He is in a relationship with Kobra and the Lotus singer Kobra Paige, as seen from their social media accounts. The two were married on April 4th, 2020.