The figure was an 11% increase on 2019 and due to record-breaking production at Sentinel in Zambia and the "resilience" of other operations, particularly Cobre Panama, in dealing with the significant challenges brought about by COVID-19, the company said.
Copper met the company's increased revised guidance, issued in October of 750,000-785,000t, following earlier reductions due to COVID-19 and the deaths of several employees at its Panama operation.
Gold was ahead of revised, lifted expectations of 245,0000-260,000 ounces.
Gold production was up from 257,000oz in 2019 to 265,000oz, according to preliminary figures.
The Ravensthorpe nickel operation in Western Australia, which resumed production in 2020, produced 6,000t in the December quarter taking full-year output to 13,000t and just meeting reduced guidance of 13,000-15,000t.
The company said final production figures would be released with its financial results.
First Quantum put 2021 copper guidance at 785,000-850,000t, increasing to 805,000-860,000t in 2022 and 820,000-880,000t in 2023.
Gold output was forecast at 280,000-300,000oz in both 2021 and 2022, and 290,000-310,000oz in 2023.
Nickel production was expected to grow to 23,000-27,000t this year, 25,000-30,000t in 2022 and 27,000-32,000t in 2023.
First Quantum said capital spending in 2020 was about US$50 million lower than previous guidance of $675 million.
It put capex at $950 million for 2021 and 2022, which included $40 million each year on the smelter expansion at Kansanshi in Zambia and about $100 million in capex deferred from 2020.
Capex of $1.05 billion in 2023 included $270 million for the proposed S3 expansion at Kansanshi.
However the company warned the project was subject to board approval "and the timing could be accelerated or delayed depending on capital availability, commodity prices and the Zambian fiscal regime".
First Quantum shares (TSX: FM) were trading about C$10 a year ago and reached a one-year high of $26.72 earlier this month.
They lost 7.3% yesterday to close at $21.35, capitalising it at $14.7 billion (US$ billion).