The song was written at the ocean's point of view, from which the singer believes all life emerged, and details the human's evolution, whilst accompanied by a choir.

"Oceania" was generally well received by music critics, who believed it was the best track from Medúlla, although some thought it was not the best choice for a promotional release.

The accompanying music video for the song, directed by Lynn Fox, features Björk as "Mother Oceania", whilst being jewel-encrusted in dark watery depths, with a colourful sunset and swirling floral creatures above her.

The singer revealed that the committee asked her to do a kind of "Ebony and Ivory" or "We Are the World" type of song, which are "smashing tunes" according to her, but she thought, "'Maybe there's another angle to this'.

Then, she called Sjón, an Icelandic poet who had previously collaborated with her on songs such as "Bachelorette" from her fourth studio album Homogenic (1997).

The song is written from the point of view of the ocean that surrounds all the land and watches over the humans to see how they are doing after millions of years of evolution.

[2] During an interview with British radio station XFM, Björk explained its recording process, saying work on "Oceania" was kept being delayed because she wanted to do it especially for the Olympics.

[4] According to Jason Killingsworth from Paste magazine, it calls listeners' attention to "Mother Oceania" from which the singer believes all life emerged, whilst she sings: "You have done well for yourselves / Since you left my wet embrace / And crawled ashore […]".

The song anchors the midsection of Medúlla, "jubilantly punctuated with bubbling synth and propelled by the rolling, spitfire cadence of Rahzel's beatbox", according to the reviewer.

[7] Entertainment Weekly's writer Chris Willman commented that "the computer-enhanced choir behind Björk [suggests] a cosmic harem of pleased dolphins.

Then, Kelis recorded her vocals at Electric Lady Studios in New York City,[9] and wrote her own words in the song, from the point of view of the continents.

[10] Originally not intended to be commercially released, the remix leaked after being played on BBC Radio 1's The Breezeblock, but was then included on the "Who Is It" single as a B-side.

Then, she experimented with different ways to space the progression of chords that runs through the piece - I suggested big, Brahmsy blocks - as well as the ending, for which we tried diaphanous, Debussy-like arpeggios".

[8] Alex Ross, reporter writing for The New Yorker stated that with "Oceania", Björk "confirmed her status as the ultimate musical cosmopolitan", acquainted with Karlheinz Stockhausen and the Wu-Tang Clan.

[13] Matthew Gasteier from Prefix magazine called the track "the best song on the album", whilst complimenting "its swooping chorus [which] recalls the migration of birds or the time-elapsed drifting of icebergs, a swirl of beauty and power crashing down onto and then rising above the mix.

Club, in a positive review, "the electronic flourish strays from her organic vocal focus, but Björk summons the same kind of tingle with choral language" in the song, "which finds The London Choir reacting to what sounds like a thrilling slow-motion circus act".

[17] AllMusic's Heather Phares noted that the song, along with Medúlla's lead single "Who Is It", "have an alien quality that is all the stranger considering that nearly all of their source material is human (except for the odd keyboard or two)".

[18] Dominique Leone of Pitchfork thought "Oceania" was hardly the most obvious choice for a promotional single release, despite its "bizarre, swooping soprano lines and cyclical chord progression outlined by a chorus of Wyatt vocal samples".

[20] The accompanying music video for "Oceania" was directed by Lynn Fox, and was premiered on August 13, 2004 through Björk's official site.

[24] At the 2004 Summer Olympics Opening Ceremony, where Björk premiered the song, she wore a very large dress which unfolded during her performance of "Oceania" to eventually occupy the entire stadium, and showed a map of the world in sign of union.

[4] Dominique Leone of Pitchfork was surprised by the committee's choice of bringing Björk to perform at the ceremony, and stated: "They could have had anyone-- say, a reassuring Celine Dion or a physically ideal Beyoncé-- but they chose a prickly, decidedly uncomfortable Icelandic woman.