Murphy, a black cockapoo, was spotted tied to a lamppost in Auchinairn Road in Bishopbriggs, East Dunbartonshire, at around 1am today.
He had been missing since the car he was inside was taken from outside the Virgin Active health club on Strathblane Road, Milngavie, on Tuesday.
Police were alerted by a member of the public who reported seeing the dog this morning. Officers said Murphy is "safe and well" and has been returned to his "delighted" owner.
The dark grey Volkswagen Scirocco is still missing.
Chief Inspector Rob Hay said: "I am very pleased that Murphy has been found and grateful to the member of the public who alerted police. There was concern in the local community for the safety of the dog but fortunately he is well.
"It is still unclear whether the thieves let the dog out of the car before driving off or decided to return it to the area due to the media interest.
"I would appeal to anyone who saw the dog being tied to the pole in Auchinairn Road or has any information on the identity of the suspects or whereabouts of the car to come forward."
Police can be contacted on 101, while Crimestoppers can be reached on 0800 555 111.