When The Straits Times visited the outlet at 10am, half an hour before it officially opened, an orderly line of more than 90 people had already formed.
Some of them were seasoned Shake Shack customers.
New York native Ted Toth, 52, joined the queue with his wife Nova, 53, at 10am.
Mr Toth, who is based in Singapore and owns an energy services company, said: "I go back to America four or five times every year and eat at Shake Shack at least twice during each visit.
"I couldn't be happier that it has opened in Singapore, and I'm sure I'm going to gain a lot of weight."