Into the Electric Castle – A Space Opera is the third album of the progressive metal project Ayreon by Dutch singer, songwriter, producer and multi-instrumentalist Arjen Anthony Lucassen. Released in 1998, it was the band's first double album.

Like most Ayreon albums, it is a concept album, taking place in the same fictional universe as Ayreon's first album The Final Experiment. Into the Electric Castle follows eight characters from different locations and time periods, who inexplicably find themselves in a strange place where they follow a mysterious voice to reach the Electric Castle to survive. Each character, made bombastically flamboyant with influence from B movies, is voiced by a different singer. Into the Electric Castle is the first collaboration between Lucassen and Ed Warby, who has since become Lucassen's most regular collaborator, playing drums on every following Ayreon album except Universal Migrator Part 1: The Dream Sequencer and Transitus and on most of his other projects.

The album was a commercial success and received overwhelmingly positive reviews from music critics. Lucassen released a remixed version of the album in 2018, followed by a live album featuring a full live performance of the album, titled Electric Castle Live and Other Tales, in 2020.