Isolation is the fifth studio album by Toto, released in November 1984. This was one of two albums the band made with Fergie Frederiksen as the primary vocalist, the other being their soundtrack to Dune. Isolation failed to achieve the popularity of its predecessor, Toto IV, although it achieved gold record status and gave the band their highest charting mainstream rock single Stranger in Town (No. 7). Relatively few songs from this album were featured in live performances after 1985's Isolation World Tour.
Frederiksen, singing lead on seven of the ten tracks, replaced original Toto vocalist Bobby Kimball while the band was in the recording process for the album. Kimball had recorded vocals for some of the album's tracks prior to his termination; sources differ on how many - Kimball says most of the album, whereas David Paich and Steve Lukather say around 3 or 4 songs. Some of Kimball's background vocals can be heard on the record, such as in their single "Stranger in Town", and at least one song, "Lion", had a demo recording with Kimball on lead vocals before being recorded with Frederiksen.
Allmusic's review praised the performances of Jeff Porcaro, David Paich, and Steve Lukather in passing but dismissed Isolation as "a Journey clone album, minus the aching ballads that had made Journey such a success."