The Theater Equation is a 2016 live album and DVD/BluRay by Arjen Anthony Lucassen's progressive rock/metal rock opera project Ayreon. The Theater Equation consists of a live performance, with cast, choir and small orchestra, of the 2004 album The Human Equation. It marks the first time an Ayreon album was played live entirely, and the first Ayreon live release.

Over four nights at Tilburg's 013 venue (scene of the Ayreon Universe series of live shows in 2017) Lucassen, his band and one of modern progressive music's most emphatic of casts celebrated the 20th anniversary of the third Ayreon album in front of thousands of adoring fans who had flown in from around the world. The entire album was performed live, featuring original album singers and musicians, such as Thijs Van Leer, Fish, Damian Wilson, Edward Reekers, Anneke van Giersbergen, and several special guests including Simone Simons (Epica) and Star Trek's John De Lancie as narrator. The 'Other Tales' are deep cuts from Arjen Lucassen's other projects, such as The Gentle Storm, Ambeon, Stream of Passion, Guilt Machine, Star One, his solo-album Arjen Anthony Lucassen and a very special Marillion cover.