The annual event is usually held during New Zealand Fashion Week but was held online this year because of Covid-19 restrictions.
Simpson-King has been a self-employed interior designer in Dunedin for about 10 years and has worked multiple major refurbishments in Dunedin, such as John Wickliffe House and the University of Otago's clocktower and St David Lecture Theatre.
Winning the award for the casino's refit was "very exciting", Simpson-King said.
Inspired by the history of the building, she did extensive research into its architecture and the era it was built.
"I really wanted to make the Grand Casino grand," Simpson-King said.
She said colour was the key to her design, making it "light but dramatic enough for a casino".
"It had to be grand, it had to be elegant and also impressive."
Previously the area's floor was a dark colour with a light ceiling, but Simpson-King decided to flip that.
The ceiling was now metallic and gold with the floor and furniture a lighter colour.
Simpson-King had six months to do the refit and had to get it done before the casino reopened with its new name in April.
Being able to do a refit like the casino's was a "dream job" for any designer.
"It is one of those jobs you have to think deep and pull on every resource to make it that special place," Simpson-King said.
