The 22nd Congress of the International Association for the History of Religions is the latest in more than five conferences the city has attracted this year.
All of the conferences are scheduled to be held in the city in the next four years.
Enterprise Dunedin Business events tourism adviser Bree Jones said the latest conference would be held in September 2020.
The five-day event was expected to attract about 600 delegates, equating to 3000 room nights, she said.
The conference would be held at the University of Otago, and members of the religious studies department would run it in conjunction with the New Zealand Association for the Study of Religion.
Associate Prof Will Sweetman of the University of Otago religious studies department said the conference provided an opportunity to bring ''outstanding scholars'' of religion from throughout the world to Dunedin.
The University of Otago's international profile was a key contributor to attracting such conferences, Ms Jones said.
''Promoting Dunedin and New Zealand as a knowledge centre continues to pay dividends, as it gives us a unique proposition globally.
''These conferences deliver vital economic benefits to our city and surrounding regions as they bring high-yield delegates during our off-peak season.''
The university and Enterprise Dunedin worked on the bid for about four months, she said.
Other conferences include:
The 9th World Congress of Herpetology, 2020, 1000 delegates, value to Dunedin economy $1.2million.
Society for the Preservation of Natural History Collections and Taxonomic Databases Working Group Joint Conference, 2018, 350 delegates, value to Dunedin economy $630,000.
The 54th World Congress of the International Sociology of Sport Association, 2019, 300 delegates, value to Dunedin economy $525,000.
