It depends on what you consider a 'hit'. They had a big hit with Ring Ring in Sweden. But their first number 1 outside of their own country was Waterloo which reached number 1 on American charts (and others such as Australia).
ABBA has had a lot of hit songs, but their most known is Dancing Queen.
I think it was Ring Ring in 1972.
The first ABBA single to reach number 1 anywhere in the world was "He Is Your Brother", their second single, released on Nov. 1, 1972. It hit #1 on the Swedish radio chart, Tio i topp. The first ABBA chart-topper outside Sweden was "Ring Ring", which reached #1 in Belgium in 1973. Their first #1 in a predominantly English-speaking country (U.K., Ireland) was Waterloo in 1974. The first ABBA #1 in Australia was "I Do, I Do, I Do, I Do, I Do" (1975). In the U.S., ABBA's first #1 was "Fernando" (1976, on the Adult Contemporary chart; their first and only #1 on the American pop/rock chart was "Dancing Queen", later in 1976).
ABBA first Album is the Ring Ring album.
You can google that and hit images, and Youtube has tons of ABBA videos even their earliest work.
Ring Ring.
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.
One favorite hit is SOS. The lead voice for this ABBA hit belongs to Agnetha.
ABBA has had a lot of hit songs, but their most known is Dancing Queen.
I think it was Ring Ring in 1972.
The first ABBA single to reach number 1 anywhere in the world was "He Is Your Brother", their second single, released on Nov. 1, 1972. It hit #1 on the Swedish radio chart, Tio i topp. The first ABBA chart-topper outside Sweden was "Ring Ring", which reached #1 in Belgium in 1973. Their first #1 in a predominantly English-speaking country (U.K., Ireland) was Waterloo in 1974. The first ABBA #1 in Australia was "I Do, I Do, I Do, I Do, I Do" (1975). In the U.S., ABBA's first #1 was "Fernando" (1976, on the Adult Contemporary chart; their first and only #1 on the American pop/rock chart was "Dancing Queen", later in 1976).
ABBA first Album is the Ring Ring album.
1970s
Since the question doesn't specify 'first what' I will have to say their first hit was Ring Ring in 1972.
I believe that ABBA's last really big hit was The Winner Takes It All.
Lasse Halstrom, later an Oscar-nominated director, directed most Abba videos and the feature film Abba: The Movie. In fact he was one of the pioneers of music video. Abba's videos were probably the first to play a significant role in selling a music act to new audiences.
Their biggest hit around that time was I Have A Dream.