The hotel opened in 1971 as The Mandarin Singapore, occupying a single 36-storey block facing Orchard Road. Designed by Cyrus Casper Francis, it had 700 rooms. Atop the hotel was the Top of the 'M' , the highest revolving restaurant in Singapore. It has since been converted to a club lounge, open to guests who belong to the hotel chain's loyalty program.
The hotel added a second block in the rear, standing 40 storeys and 152 metres high, in 1973. With the addition, designed by Lee Sian Teck Chartered Architects, the hotel became the tallest building in Singapore.[5][6]
The hotel was renamed Meritus Mandarin Singapore in 2002.[7] It underwent a S$200 million renovation in 2009. The ground level lobby and the lower levels were converted to a shopping mall, The Mandarin Gallery. The hotel lobby was relocated to level 5, beside the swimming pool.[8] At the conclusion of the renovations, in 2010, the hotel was renamed the Mandarin Orchard Singapore.[9]