Kaylee Davidson-Olley, who underwent the historic procedure 25 years ago, was joined by more than 30 people who have since had the operation as babies.
She made medical history at just five months old when she successfully received a heart transplant at Freeman Hospital, Newcastle, on October 14, 1987.
Since then 112 children under the age of one, from across the country, have received new hearts.
Ms Davidson-Olley, 25, said: "I cannot believe that I am fit and healthy 25 years after my heart transplant. I feel overwhelmed, excited and very emotional.
"This was only made possible because of the generosity of a family who made that important decision about organ donation, a decision that saved my life.
"I hope my own story and that of all the children at this special event will encourage others to be involved, if only to just talk about organ donation with their family."
Ms Davidson-Olley, who balances studying at college with a busy athletics schedule, has just been selected to represent Great Britain at the World Transplant Games in Durban, South Africa in July next year.
Dr Richard Kirk, a consultant paediatric cardiologist at the Freeman, said: "We are very proud of Kaylee and urge parents to consider organ donation, despite incredibly difficult circumstances."