US Olympic swimmer Missy Franklin received a rendition of 'Happy Birthday' from Prince Harry.

Franklin, who dominated in the pool during the London Games last summer, was in attendance at a cocktail reception at the Sanctuary Golf Course in Denver on Friday to welcome Prince Harry to Colorado.

During the event, the crowd as well as the Prince sang birthday wishes to Franklin, who recently turned 18 years of age.

The swimmer wrote on Twitter: "And the perfect way to end my 18th birthday!? Meeting Prince Harry! It was a honor meeting him and I had a blast as always."

Franklin has four gold Olympic medals and one bronze.