A Rotherham resident could be £50,000 richer, but time is running out to find the winner.
The winner has until February 23 to claim the prize from the ticket which was drawn on August 27, 2016.
It was bought in the Rotherham Metropolitan Council area. The winning code is GREY 1431 4050.
One millionaire was created for each of Team Great Britain's 27 medal winners from the Rio Olympics.
Twenty three prizes of £100,000 were given out to match the silver medals, and there were 17 £50,000 prizes. The Rotherham ticket is one of those.
National Lottery's senior winners' advisor, Andy Carter. said it was important the winner was found.
“We’re eager to find Rotherham’s mystery ticket-holder and unite them with their winnings – this amazing prize could really make a huge difference to somebody’s life," he said.
The National Lottery has invested more than £5 billion in grassroots sport to date, with Rotherham Community Sports Trust just one of those that has benefited.
Rotherham United Football Club and its Community Sports Trust, which has received almost £400,000 worth of National Lottery funding, are jointly helping in the search for the missing ticket-holder.
The trust, which aims to get as many people as possible engaged in sport and leading healthy lifestyles, has used its National Lottery funding to focus on inclusion, mental health and specific outreach projects in the local community to ensure everyone has access to sporting facilities. These include everything from football and fishing, to curling and table tennis.
The head of the trust at Rotherham FC, Jamie Noble, said: “The trust relies on charitable donations. The funding we received from The National Lottery has allowed us to engage with even more people and encourage more people than ever to make use of and benefit from our facilities.
“We are delighted to support the hunt for the missing ticket-holder and hope we find that lucky Rotherham winner.”