"We've been working on it for a little while," Creedy said. "If you took a walk up and down Queen St you might start to see some building activity."
Carl's Jr will join McDonald's and Burger King, which already operate two and three stores each on Queen St, respectively, while Wendy's has one restaurant on the shopping strip.
McDonald's and Burger King also have stores in the Westfield Downtown shopping centre.
There are numerous other independent fast-food businesses - such as kebab shops - and a new Asian food court will soon open at the Queen Street Markets, in the old MidCity Cinema centre.
Creedy said the company did not see the heavy competition as a problem, rather an opportunity to pinch other fast-food operators' customers. "There's a lot of people [on Queen St] and a lot of business."
Friday and Saturday night social crowds, who gravitate towards the burger joints after they have finished hitting the bars, were an added bonus.
But Creedy would prefer the Carl's Jr store to open only until 1am or 2am on the weekends, not 24 hours, because round-the-clock restaurants were difficult to operate.
At the Restaurant Brands annual meeting on Friday, Creedy said the company planned to open 25 Carl's Jr stores over the next five years.
"We have a great deal of enthusiasm for this brand and believe it has the potential to be our second biggest business [after KFC] within the next five years," he said.
Yesterday, he said Restaurant Brands had the capacity to grow to the point where it operated eight to 10 separate food chains in New Zealand.
Steakhouses, ice cream, pie and sushi stores are all "areas of interest" the firm has said it could expand into.
Creedy was not keen to name any of the businesses the company was interested in, but said Restaurant Brands hoped to add a fifth brand to its portfolio within the next two to three years, and the sixth within the next five years.
Restaurant Brands shares closed steady yesterday at $2.10.