The album tells the story of an alien race and their journey to a new world due to catastrophe. Olias, the title character, is the chosen architect of the glider Moorglade, which will be used to fly his people to their new home. Ranyart is the navigator for the glider, and QoQuaQ is the leader who unites the four tribes of Sunhillow to partake in the exodus.
The album's concept may have been partly inspired by the cover art for the 1972 Yes album Fragile, which depicts a tiny planet breaking apart and a glider escaping into space. Another link to Fragile lies in the fact that both albums have pieces (Fragile's "We Have Heaven") consisting of multiple vocal parts, with Anderson singing all of them. Anderson has stated that works by J.R.R. Tolkien were also an influence, underlying the epic scope of the narrative compressed into the album.
The album is considered to be one of Anderson's better works, being acclaimed both by critics and fans, and possibly the best solo effort by any member of Yes. Anderson heavily relied on the Moog synthesizer to create the soundscapes of the album, and through months of effort achieved arrangements of musical virtuosity that he has been unable to match in later solo works. (Many later works, such as Animation, relied on session players.) Since Anderson produced Olias soon after Vangelis had auditioned to be a part of Yes, there has been widespread speculation that Vangelis contributed to the album, with some fans going so far as to say that Olias represents the kind of sound that Yes would have created if Vangelis had in fact joined the band. However, both Vangelis and Anderson have denied that they collaborated on the album, and it must be noted that Olias sounds markedly different to the five albums that Jon and Vangelis did actually produce together in the late 70s and early 80s.
The album has been re-released several times, most recently with a US CD release by Wounded Bird Records on February 28, 2006.