The grand edifice of the National Museum of Singapore, with its wide façade and a large dome, has been a prominent landmark on Stamford Road for over a century. Dedicated to the art, culture and history of the country, it is the oldest museum in the country and traces its history to the early years of Singapore’s colonial era. The museum, one of the largest museums in Asia, exhibiting sculptures, objects d’art, paintings, drawings and archaeological finds, is one of six national museums and one of the national monuments of the country, having been designated as such in 1992, by the National Heritage Board.

Although a meeting was held in 1823, to discuss a proposal to establish a museum for the revival of the region's cultural heritage, no action was taken during the next two decades to materialise it until 1843, when the Temenggong of Johor gifted two gold coins to the Singapore Institution.

After that, a small museum was set up by the then Singapore Institution Committee in a section of the library of the Institution in 1849, which would later become Raffles Library and Museum. However, due to the steadily increasing growth of its collection, the museum was moved to the Town Hall in 1874, only to be shifted back to the new wing of the Singapore Institution in 1876, to solve its space problem. Finally, a decision to construct a proper building for the museum was taken in 1882 and commissioned by the colonial government, the project began in 1884 and the building was completed three years later. The new building of the Raffles Library and Museum, constructed on Stamford Road was officially opened by Sir Frederick Weld, Governor of the Straits Settlements on 12 October 1887, to mark the Golden Jubilee of Queen Victoria.

Primarily, the museum was intended to be a repository of zoological specimens, documenting the natural history of Singapore, as well as the rest of Southeast Asia, especially the Malay Peninsula and the island of Borneo. However, the initial years of the museum, housed in the grand edifice, were plagued by numerous problems and challenges. While termite invasions rendered part of the roof structurally unsound, Zoological specimens kept in the museum often suffered mould growth.

But despite everything, it soon became a centre of research and knowledge and the seat of the editorial office of the Journal of the Malayan Branch of the Royal Asiatic Society, often visited by scholars who were en route their trips around the region. Further extensions of the building, consistent with the architecture of the original block, were carried out in 1906, 1916, 1926 and 1934, to provide sufficient space for the growing number of artefacts and books.

The museum separated from the library in 1960, when its name was formally changed from Raffles Museum to the National Museum of Singapore. After that, the zoological specimens were shifted to the Zoology Department of the University of Singapore, now known as the National University of Singapore, in 1972, making it possible for the museum to focus itself solely on history, ethnology and art of Singapore. For a brief period between 1993 and March 2006, it was known as the Singapore History Museum, before subsequently reverting to its original and present name in 1965.

The building of the museum reflects a seamless fusion of old and new, which enhanced the elegance of the neo-classical building with a new modernist extension of glass and metal.

Originally designed by Colonial Engineer Sir Henry E. McCallum, which was subsequently revised by J.F. McNair, who scaled down the initial design, the original structure, the front block of the present building, is largely Neo-Palladian in style and consists of two rectangular parallel blocks, with a dome at the front of the building and a rotunda. The rotunda is crowned with a dome covered with 3000 fish-scale tiles made of zinc and stained glass panels and arched windows, allowing infiltration of natural light to illuminate the interior space. There is a new glass-clad, cylindrical rotunda at the rear area of the building, made up of two drums, with the outer one made of glass which sheaths an inner one made of wire mesh.

In 2000, the government decided to double the capacity of the National Museum of Singapore and update its contents without demolishing previous expansions. In 2002, the museum building was temporarily closed for three and a half years, when it underwent a revamp and a new annexe block was constructed behind the old building, on the site of the demolished Drama Centre. The foundation stone ceremony of the new building, twice as large as the old one, was held on 25 November 2004 and its structural top out was celebrated on 28 November 2005.

Apart from the construction of the annexe, massive redevelopment work was undertaken, which consisted of repairing the damaged parts and restoration of the hidden or badly damaged architectural features. Accordingly, the fish scaled tiles were all taken down and cleaned or replaced and a long-lasting titanium-zinc-based coating was used to protect them from oxidation and erosion. While the stained glass panels were all taken down, inspected and cleaned, a spiral staircase leading to the roof of the old museum building was restored and modern staircases were installed in the building to contrast the old and new. As the details of the balustrades on the second floor were hidden under years of paint, the old coats of paint were removed and a special type of clear coat was applied to protect the wrought iron from rusting, as well as to allow the details to be visible. While new plaster works were carried out on the deteriorated or destroyed motifs, capitals, cornices, balustrades and carvings, the most important job done was the restoration of the entire northern façade and the coat of arms of Queen Victoria, which had been destroyed.

Today, the National Museum of Singapore, covering an area of 198,000 square feet, is distributed among three parallel, but linear blocks. The original building, facing Bras Basah City Park, is followed by an early-20th-century addition and then the most recent construction, overlooking Fort Canning Park. The new glass clad building of the museum, designed with the old building still remaining as the centrepiece of the museum, houses the Singapore History Gallery, featuring the history of the country from the 14th century. A ramp spiral in the new building leads down to an exhibition space housing the nation's treasures, which includes the huge Singapore Stone bearing an undeciphered inscription, which originally stood at the mouth of the Singapore River, believed to be as early as the 10th or 11th century. Its exhibits also include several 14th century gold ornaments unearthed from nearby Fort Canning Hill in 1928. The new block houses the children’s discovery gallery above ground, the history gallery in its first basement, along with the temporary galleries and a 250-seat auditorium in its second basement, while the Stamford Road block contains restaurants, shops, and offices on the ground floor and thematic galleries upstairs.