Pharrell Williams has scored his third chart-topping single of the year with ‘Happy’.

Earlier this year Pharrell Williams landed at No.1 with Daft Punk and Nile Rodgers on ‘Get Lucky’ – the second bestselling song of 2013 with sales of 1.28 million.

He later teamed up with Robin Thicke and T.I. for ‘Blurred Lines’ – which sold 1.44 million copies in the UK, making it the biggest seller of the year.

‘Happy’ is taken from the film ‘Despicable Me 2’ and has sold over 107,000 units in the last week.

Pharrell Williams failed to gain the Christmas No. 1 spot last week but has now toppled the X Factor’s Sam Bailey, whose cover of Demi Lovato’s ‘Skyscraper’ now sits at No. 2.

The rest of this week’s top five is made up by Avicii’s ‘Hey Brother’ up two to No. 3, ‘Trumpets’ by Jason Derulo up four to No. 4 and ‘The Monster’ by Eminem featuring Rihanna up four to No. 5.

The only new entry to this week’s Top 40 comes from Beyoncé and Jay Z with ‘Drunk In Love’ which has climbed 28 places to reach No. 29.

Watch the video for 'Happy' below: