Official Charts Company (OCC) data showed that the song sold almost 124,000 copies in the first week of its release.
Sing is the second single to be taken from his new album, X. The predecessor, One, peaked at number 18 in May after just 48 hours on sale.
Commenting on his success, Ed said: ‘It’s fantastic. It’s nice to finally have a number one in my home country. Thank you to everyone who supported the single for making this happen.’
Previously, Ed penned One Direction’s 2012 chart topping single, Little Things and had 12 top 40 hits in his own right,
Meanwhile, Dame Vera Lynn has made British chart history by becoming the oldest living artist to reach the top 20.
The singer, who celebrated her 97th birthday in March of this year, entered the UK’s album chart at number 13 with her new collection, Vera Lynn: National Treasure.
The double album, compiled by Decca Records, features such iconic songs as We’ll Meet Again, (There’ll Be Bluebirds Over) The White Cliffs Of Dover, and How Green Was My Valley.
This year Dame Vera Lynn celebrates 90 years in show business, having made her first professional performance at the age of seven.