On 8 January 2011, Sheeran released another independent EP, No. 5 Collaborations Project, featuring grime artists such as Wiley, Jme, Devlin, Sway and Ghetts. With this EP, Sheeran gained mainstream attention for having reached number 2 in the iTunes chart without any promotion or label, selling over 7,000 copies in the first week. Three months later, Sheeran put on a free show to fans at the Barfly in Camden Town. Over 1,000 fans turned up, so Sheeran played four different shows to ensure everyone saw a gig, including a gig outside on the street after the venue had closed. Later that month, Sheeran was signed to Asylum Records.
On 26 April 2011, Sheeran appeared on the TV music show Later... with Jools Holland, where he performed his debut single "The A Team". Six weeks later, "The A Team" was released as a digital download in the UK. The release served as the lead single from Sheeran's debut studio album, + (pronounced "plus"). "The A Team" entered the UK Singles Chart at number three, selling over 58,000 copies in the first week. It was the best-selling debut single and the overall eighth-best selling single of 2011, selling 801,000 copies. The lead single also became a top ten hit in Australia, Germany, Ireland, Japan, Luxembourg, New Zealand, Norway and the Netherlands. During a headline set in the BBC Introducing tent at Glastonbury Festival 2011, Sheeran announced that "You Need Me, I Don't Need You" would be released on 26 August as the second single from the album. The second single peaked at number four on the UK Singles Chart. "Lego House" was released as the third single, reaching the top ten on the Australian, Irish and New Zealand Singles Charts. The music video for “Lego House” features Harry Potter actor Rupert Grint, as a play on their similar appearance. "Drunk", released on 19 February 2012, became Sheeran's fourth consecutive top ten single in the UK, peaking at number nine.
Sheeran released + on 12 September 2011. The album received generally favourable reviews from music critics. + debuted at number one on the UK Albums Chart for sales of 102,000 copies. By end of 2011, sales of the album in the UK stand at 791,000; it became the second best-selling debut album and the ninth biggest-selling album there. The album has been certified platinum six times by the British Phonographic Industry, denoting shipments of 1,800,000 copies. As of March 2012, the album had sold 1,021,072 copies in the UK. The album also reached the top five in Australia, Canada, Ireland, New Zealand and the US.
The song, "Moments", on the debut album by boy band One Direction, released in November 2011, was co-written by Sheeran. At the 2012 Brit Awards on 21 February, Sheeran won the Brit Awards for Best British Male Solo Artist, and British Breakthrough Act of the Year. On 10 January 2012, it was announced that Sheeran would support Snow Patrol on their US tour from late March until May. His song, "Give Me Love", was featured in the episode "Dangerous Liaisons" of The Vampire Diaries. At the Ivor Novello Awards in May 2012, Sheeran's "The A Team" bested Adele's "Rolling in the Deep" and Florence and the Machine's "Shake It Out" for Best Song Musically and Lyrically. Sheeran performed "The A Team" at the Diamond Jubilee of Queen Elizabeth II concert held on The Mall outside Buckingham Palace on 4 June 2012 and a cover of Pink Floyd's "Wish You Were Here" at the closing ceremony of the 2012 Summer Olympics in London on 12 August 2012.
In early 2011, after securing recording and publishing deals, Sheeran purchased and renovated a farm near Framlingham, Suffolk, where he was raised. He has stated that he hopes to raise a family there. During 2013, he lived between Hendersonville, Tennessee and Los Angeles, California. In 2014, he bought a house in South London.