"Happy" was featured on the soundtrack for the animated film Despicable Me 2, and hasn't left the top 20 since December.
Music industry body BPI helped the numbers when it began counting online streams as part of its sales awards -- with 100 streams equaling one online sale. "Happy" was streamed more than 25 million times, adding approximately 250,000 sales to its numbers.
"Every now and then a song comes along that captures the public mood and becomes a feel good anthem for a generation," said BPI spokesman Gennaro Castaldo. "'Happy' is not only one of the most successful multi-platinum recordings of all time, it has taken on near-iconic status and has helped to propel Pharrell to global superstardom."
The song has reached global audiences, even prompting some to make their own music videos in defiance of the government.
Will Young's "Evergreen," Aqua's "Barbie Girl," and Elton John's "Candle In The Wind" are the only three other songs to hit triple-platinum status.