The orchestra leader Stephen Morris is back in possession of the 1709 David Tecchier instrument that he left late at night last week on a suburban train.
Police say the violin was handed over in a supermarket car park in Beckenham after secret negotiations. Earlier, police published a photograph of a person of interest. An individual contacted Morris by Twitter.
The man who returned the violin said he had made a mistake and apologised. Police say no further action will be taken.