Trans-Siberian Orchestra is a rock orchestra founded by Paul O'Neill, Robert Kinkel, and Jon Oliva in 1996. O'Neill had managed and produced rock bands including Aerosmith, Humble Pie and Scorpions, later writing for and producing Savatage, where he began working with Kinkel and Oliva.

The roots of TSO are found in Savatage, a traditional heavy metal band that gradually progressed into an operatic metal act. Savatage's rock operas, starting with STREETS, began the experimentation with what would become TSO culminating on the track "Christmas Eve (Sarajevo 12/24)" from DEAD WINTER DEAD. This track was a minor hit for the struggling band, and demonstrated that there might be an audience for the symphonic metal approach to holiday themes.

The concept for a band playing Christmas carols in a rock opera style was not received warmly by the industry, but quickly proved a success with adults as well as young people. In the recording studio, Trans-Siberian Orchestra uses a full 60-piece orchestra and a choir.

As of 2004, their touring band included 14 vocalists, 14 musicians, and 2 narrators. Trans-Siberian Orchestra released their debut album Christmas Eve and Other Stories in 1996, and it remains their best-selling album. Their 1998 release The Christmas Attic was similarly a concept album with a Christmas theme. In 2000, they released their first (and to date only) non-Christmas album, Beethoven's Last Night. Beethoven's Last Night is a concept album about Ludwig van Beethoven's last night on earth, during which he meets Mephistopheles.

After a few years of touring, they returned to the studio with another full-length album, Lost Christmas Eve, and the accompanying DVD/3-CD release The Christmas Trilogy, which contained all three of their Christmas albums to date. The band is, as of early 2005, working on a new non-Christmas album, Nightcastle. It is projected to be released sometime in October of 2007 and is expected to feature the band's rendition of "Carmina Burana (O Fortuna)", performed as a preview by the band during their 2004 and 2005 tours.