The wardrobe, described as nationally significant, will be looked after by Stage South, a group of theatre professionals who got together after the Fortune closed last month.
The Fortune Theatre Trust announced in early May the facility was no longer financially viable.
It emerged this week the wardrobe would be kept in the city after the Dunedin City Council paid $4000 towards its $10,000 cost, the Friends of the Fortune paid the same amount, and a private donor the rest.
The money was used to pay the trust for the wardrobe on behalf of Stage South.
Stage South steering group member Cindy Diver said the group's main focus was to retain the wardrobe in Dunedin for use by locals.
The actors, writers, directors and others who made up Stage South - in the process of becoming a charitable trust - wanted to find a way to sustain professional theatre in Dunedin.
"One of the key aspects is to maintain the key asset of the amazing wardrobe which has been gathered over the last 40 years.
"Luckily we have been able to do that."
The wardrobe would continue to be housed at King Edward Court, in Stuart St.
Ms Diver said her company, TheatreWorks Ltd, had provided sponsorship for rent and maintenance of the wardrobe for the next six months, until Stage South was up and running and could find a way of funding it.
Ms Diver said the costumes would primarily be an asset for Stage South, but with enough funding the wardrobe would be run in a way similar to how was in the past, when school groups and others could use it.
"That's a bit further down the line, because we don't have those processes in place to allow that to be done yet."
Ms Diver said the wardrobe was "absolutely" nationally significant.
"There are costumes in there that are vintage costumes of an era you just couldn't get a collection like that easily.
"There are some costumes in there that I don't know if anyone else in New Zealand has got.
"There is a lovely array."
Fortune board of trustees chairwoman Haley van Leeuwen said she was delighted Stage South had taken ownership of the wardrobe.
It was sold, rather than donated, because the trust had a fiduciary responsibility to repay creditors, and planned to appoint liquidators to sell the theatre's assets.
The trust planned to sell all the theatre's remaining assets by auction, and was planning a special general meeting on July 9, at the Dunedin City Library, to ratify a resolution to dissolve the trust and appoint liquidators.
