ABBA - S.O.S - On ABBA Album (1975)

"SOS" was the third single from Swedish pop group ABBA's self-titled 1975 album, their third for Polar Music and their second for Epic and Atlantic. It was released with "Man in the Middle" as the B-side. Agnetha Fältskog, who sang lead, recorded the song in Swedish on her 1975 solo album Elva kvinnor i ett hus. "SOS" was ABBA's first major worldwide hit since "Waterloo" and, to date, is the only Hot 100 single (or #1 single in Australia) in which both the title and the credited act are palindromes.

"SOS" marked a huge turnaround in ABBA's fortunes, most notably in the UK and Ireland, where it returned the group to the Top 10 for the first time since "Waterloo". Reaching #6 and #4 respectively, "SOS" started a run of 18 consecutive Top 10 hits for ABBA in the UK and Ireland. "SOS" reached #1 in Australia, Belgium, France, West Germany (where it spent 7 weeks at the top), New Zealand and South Africa, and was a Top 3 hit in Austria, the Netherlands, Norway, Italy (where it became ABBA's most successful hit), Mexico, Rhodesia and Switzerland. The song also became ABBA's second Top 20 hit in the United States, peaking at #15 (due to the single charting in the U.S. before "I Do, I Do, I Do, I Do, I Do", whereas elsewhere "SOS" charted afterwards).

Chicago radio station WLS, which gave "SOS" much airplay, ranked the song as the 61st biggest hit of 1975. It peaked at number six on their survey of 22 November 1975.

"SOS" is one of the most-covered of ABBA's songs. It has been recorded and performed in concert by several prominent artists, including John Frusciante, Peter Cetera, and Chris deBurgh.

The track has a number of music industry devotees. The Who guitarist Pete Townshend has said "SOS" is one of the best pop songs ever written, adding that when he first heard the song he "was transported by it".

Former Beatle John Lennon declared that it was one of his favourite pop songs, while Ray Davies of The Kinks said that he was taken with the song after seeing the group perform it on the television show Seaside Special.