Transatlantic is a multinational progressive rock supergroup consisting of Neal Morse (ex-Spock's Beard), Roine Stolt (Kaipa, The Flower Kings, Agents of Mercy) , Pete Trewavas (Marillion, Edison's Children) and Mike Portnoy (ex-Dream Theater). They formed in 1999 as a side project to their full-time bands, but disbanded in 2002. They then reunited in 2009. Typical of the genre, the band's songs can range from very long epics that regularly exceed 15-20 minutes in length, to 'normal length' songs that each last five to ten minutes.

Despite not being an official member and not appearing on the studio albums, Daniel Gildenlöw (Pain of Salvation) has traditionally joined the band during live shows. However, due to illness, Ted Leonard (Spock's Beard, Enchant, Thought Chamber) stood in for him during the 2014 tour.