The charity found the hamster on Saturday, March 1 after receiving a call from a resident who had found the animal on the pavement in Dumbeg Park, Wester Hailes.
The brown and white adult male Syrian hamster is now in the care of the Scottish SPCA's Edinburgh and Lothians Animal Rescue and Rehoming Centre. He has been named Fievel.
Animal Rescue Officer Stephanie Grant said: "Fievel was found at around 4pm on Saturday afternoon inside a blue and transparent plastic tube, which looks like an attachment to a hamster cage.
"The tube was open at one end so he could easily have escaped and come to harm from nearby traffic or predators.
"I also noticed there was no food available for Fievel to eat so it's very lucky he was found alive and well.
"He's a friendly little guy who doesn't mind being handled and he's in good condition so he's clearly been someone's pet.
"However, this doesn't excuse the fact that he's been dumped on the street like a piece of rubbish.
"We'll continue to care for Fievel until we can find him a good home with a loving new owner."
Anyone with information is being urged to call the Scottish SPCA animal helpline on 03000 999 999.