Standard & Poor's confirmed on Monday reaffirmed the council's AA long-term and A-1+ short-term issuer credit ratings.
Council group chief financial officer Grant McKenzie said the "pleasing'' result reflected the hard work of council staff and councillors to limit operational spending and reduce debt.
"These consistent efforts are reflected in these ratings,'' he said.
Standard and Poor's, in its 2015 research update, said the ratings reflected its view of New Zealand's institutional framework and Dunedin's strong financial management and budgetary performance.
"The stable outlook reflects our expectations that Dunedin's financial strategy will ensure continued strong operating surpluses and declining levels of debt.''
The result came after confirmation in September the council's total group borrowings - spread across the council, its companies and including stadium-related debt - had dropped from $621 million in 2013-14 to $598 million by June 30 this year.
