ABBA's last world-wide #1 was "One of Us" (1981), which hit #1 in at least four countries. It only reached #2 in the UK though there are some who believe it probably reached #1 the next week but there was no chart published (due to Christmas holidays). "One of Us" reached #33 in the US. The last British #1 was Super Trouper (1980). In the US, ABBA's last (and only) #1 on the Hot 100 was Dancing Queen (1976) but "The Winner Takes it All" peaked at #1 on the Adult Contemporary chart in 1980 and "Super Trouper" reached #1 on the Dance chart in 1981.
1983. Their last original single, "Under Attack", reached #1 in several countries.
Abba's first-ever #1 single was "He Is Your Brother". It reached #1 on the Swedish radio play chart in 1972. The first Abba single to reach number 1 outside Sweden was "Ring Ring" (1973), which hit #1 in Belgium. "Waterloo" was Abba's third chart-topper and the first to reach #1 in an English-speaking country.
Super Trouper, 1980.
The Visitors.
See the link below for the full list of Abba single releases.
Depends what you consider to be a hit. ABBA's first chart single in the UK was Waterloo, which peaked at #1 in 1974. Their next release was "Ring Ring", which was actually a remix of a 1973 single. The 1974 version reached #32 in the UK. Their next single, "So Long" only reached #91. But in 1975, "I Do, I Do, I Do, I Do, I Do" cracked the top 40, peaking at #38. Their next top 10 was "S.O.S.", which reached #6. ABBA's next single was their second #1 hit in the UK, "Mamma Mia".
ABBA recorded for the last time as a group in 1983.
If you're thinking of Abba, as a single it reached No 2 in South Africa and No 33 in UK. But as a track on ABBAs Greatest Hits and ABBA The Movie it hit No 1 all over the world.
I believe that ABBA's last really big hit was The Winner Takes It All.
People Need Love.
Super Trouper.
There is no single answer for this question. ABBA had many songs that millions around the world loved.