Wildlife officers said algae growing in the salt crust at the bottom of Westgate Park's lake produce a red pigment.
"Enjoy the views, but we recommend you don't come into contact with the water," Parks Victoria said.
The phenomenon also occurs in Spain's Salina de Torrevieja, Canada's Dusty Rose Lake and Senegal's Lake Retba.
In Australia, the natural occurring sight can be seen in Victoria's Murray-Sunset National Park and Western Australia's Lake Hillier.
