This beats the previous record, 472,600 visitors, in the 12 months to June 30, 2008.
The figure was confirmed by figures tabled at a recent Otago Museum Trust Board meeting, which indicated 628,000 visits had been made to the museum in the financial year to June 30 this year.
Museum organisers said the museum's Tropical Forest, home to about 1000 tropical butterflies, had attracted many people to the museum.
Museum chief executive Shimrath Paul said that the "honeymoon" appeal of the Tropical Forest had lasted longer than he had predicted, but he warned that overall attendance in future could be expected to fall, perhaps to 300,000-400,000 visitors.
However, this would still be a strong result, he said.
The latest attendance figures and been carefully checked and staff believed they were valid, he said.
