Twelve-year-old Ria Shaheena was pushed over and her dog, Mika, taken in Reddings Lane Park, Tyseley in Birmingham, on Thursday afternoon.
Following appeals for information a woman in Selly Oak who suspected she had bought the three-month-old Akita dog contacted police.
Mika was taken back to her home on Tuesday morning, none the worse for wear.
Police said the woman had bought the dog, valued at Â£1,000, in good faith and urged the teenagers who had stolen the dog to contact them soon.
A vet checked Mika over and her microchip confirmed it was the stolen dog.
A tearful Ria was overjoyed to see the dog again.
"I am just so happy to see her," she said.
"I didn't think she'd come back."
A girl has been reunited with the puppy that was stolen from her in a park.