Arto Julkunen found the purple and blue balloon in woodlands Tampere, Finland on April 29 this year.
Written on the balloon on one side is the message: 'Lilly Butten, 9 years,' and written on the other side is: 'City of Sheffield'.
Mr Julkunen launched a Facebook appeal to see if he could find out whether the balloon was truly released in Sheffield.
The 56-year-old said: "My wife, my Labrador Retriever and I were having a normal Sunday walk in a forest when we found it. I first thought that 'Gosh, someone has thrown again litter in here'.
"I decided to collect it. To my surprise I saw faint writing on it - barely visible. After reading it I couldn't believe that it was really saying 'City of Sheffield'. When I read the other side, I decided that - true or not - I have to put this to Facebook. If it travelling 1,500 miles is true, it is really a wonder."
Anyone with information on where the balloon may have come from should contact him by emailing [email protected]