Carson signed professional terms during the 2004–05 season, where he was backup to Ben Alnwick for the final three games of the season. He was allocated the number 24 shirt for the 2005–06, 2006–07, 2007–08 and 2008–09 seasons. On 14 August 2008, Carson joined Chesterfield on a season long loan deal. He made his professional début on a 1–0 victory against Grimsby Town keeping a clean sheet. He was recalled early in the January after a shortage of keepers due to injuries at Sunderland. He made his debut for Sunderland on 16 July, against Darlington in the 4–0 win for Sunderland. In 2009 with Craig Gordon out through injury, Steve Bruce urged Carson to push Márton Fülöp for the No.1 spot in the squad. He signed a new contract with Sunderland on 22 October 2009 which would keep him at the Stadium of Light until 2012. He was loaned out to Lincoln City on 20 January 2011 until the end of the season. He made his debut on 22 January against Stockport County in a 4–3 win. The following season he was loaned out again in January 2012, where he went out on loaned for a month to Hull City. After showing promise at Sunderland it still wasn't enough to stay at the Premier League side, and subsequently he was released on 19 May 2012. After a short spell at the KC Stadium he was loaned out to Bury, where he made 9 appearances in Greater Manchester.
Bury
On 22 May 2012 it was announced that Bury had completed his signing on a two-year contract after impressing in his short loan spell. In his first season at Gigg Lane he made 39 league appearances, but Bury were relegated to the Fourth Tier. He was released by Bury on 1 May 2014.
On 3 October 2013 Carson joined Portsmouth in a three-month loan deal. Carson was given the number 40 shirt and made his debut in a league match against Rochdale, he kept a clean sheet in a 3–0 victory. He established himself as number one ahead of John Sullivan and Phil Smith. He set himself up to be signed up permanently in January 2014, when Carson outlined that he was keen to stay at the South Coast Club.
On 15 June 2015, Carson signed for Hartlepool after Cheltenham's relegation.
Motherwell
On 6 June 2017 Carson joined Motherwell for an undisclosed fee from Hartlepool United, on a three-year contract. On 7 January 2020, he signed a new two-and-a-half-year contract, keeping him at Fir Park until 2022.
International career
He played two games in two days when appearing for Northern Ireland U21s in Wuppertal, Germany on 5 September 2008, with his side losing 3–0, before making a dash back to Chesterfield to play in a 1–0 win over Rotherham United. He also represented Northern Ireland B in a 3–0 defeat against Scotland B in May 2009. In January 2013 he was called up to the full Northern Ireland squad for their game with Malta, but was forced to withdraw with a broken finger. In May 2015 he was called up again for a friendly against Romania. He made his international debut on 24 March 2018, against South Korea at Windsor Park.
Career statistics
Personal life
On 23 November 2018, it was reported that Carson had developed Deep vein thrombosis.
