The Singapore River is a small river in terms of physical attributes, but of extreme historical importance to the country of Singapore, the political entity which shares its name.

The mouth of the Singapore River was the old port of Singapore, being naturally sheltered by the southern islands. Historically, the city of Singapore initially grew around the port so the river mouth became the centre of trade, commerce and finance. To this day, the old Singapore river mouth is still the most expensive and economically important pieces of land in Singapore.

There have been plans announced by the Singapore government recently to dam the Singapore River at its outlet to the sea to create a new reservoir of fresh water. While damming this area would create a valuable source of fresh water for the tiny nation state, it does prevent the docking of ocean-going ships at the singapore river, which was, arguably, the original reason Singapore came into existence.

Whereas the original mouth of the Singapore River emptied into the straits between Singapore and its southern islands, nowadays, the Singapore River empties into Marina Bay an area of water partially enclosed by land reclamation work. It is also notable that the port of Singapore is now located to the west of the island (taking up most of the south-west coast) and that passenger ships to Singapore now typically berth at Harbourfront.