Before working with a rock band, he was a jouster at a Medieval Times Dinner Theater. He was introduced to the band Symphony X by former singer Rod Tyler. Allen has been the lead singer of Symphony X since 1995, releasing seven studio albums and one live album with the band. His first solo album, Atomic Soul, was released April 25, 2005. As well as singing he also plays the bass when performing songs from Atomic Soul live. He is referred to in various circles as "Sir Russell Allen", and he is credited as such on Arjen Lucassen'sStar One albums, because of a joke that Arjen made knowing Allen's former "job" as a jouster.
In addition to being on tour with Symphony X, he is also currently working on another project with guitarist Mike Orlando called Adrenaline Mob. The EP, Adrenaline Mob, was released in August 2011. The full length album Omertà was released in March 2012.
In November 2013, Allen announced that he will be touring with the East Coast touring company of Trans-Siberian Orchestra for the 2013 Fall/Winter tour.
Multi-instrumentalist, singer and composer Arjen Lucassen has said the following regarding Russell Allen:
Russell has a very powerful and versatile voice, and on top of that he is a great musician and performer. Russell was one of the few singers with whom I didn’t need to be present during recording, but when on the phone he let me hear the parts he had sung, my eyes filled with tears. Russell thought I was joking, but I was truly moved! At the moment Russell is one of the best singers in the world. And he proved that during the Star One tour.