In the United Kingdom , " Happy " debuted at No. 71 on the UK Singles Chart on December 1 , 2013 . It then spent four weeks climbing before finally reaching No. 1 on December 29 . It became Williams ' third No. 1 song in Britain , counting " Get Lucky " and " Blurred Lines " , where he appeared as a featured artist . It has since spent four non-consecutive weeks at No. 1 , reaching the peak on three separate occasions . In doing so , Williams became only the third artist ever to achieve this , and the first since Guy Mitchell in 1957 with " Singing the Blues " . Following the single 's third week at No. 1 , it spent five weeks in the top three before returning to the summit , boosted by his performance at the 2014 Brit Awards . In the same week that " Happy " returned to No. 1 for the third time , it sold its millionth copy in the UK , Williams ' third in under a year , having previously done so with Daft Punk 's " Get Lucky " in June 2013 , and Thicke 's " Blurred Lines " in July 2013 . This made Williams only the second artist in UK chart history ( the first being The Beatles ) to have three singles sell 1 million copies in under a year , as well as only the third artist ever to have three million-sellers , along with The Beatles ( who have six ) and Rihanna ( who has four )
2014 Brit Awards
2014 Brit Awards
Happy (Pharrell Williams song)