27 year old Blackburn Rovers goalkeeper Mark Bunn joined Norwich for an undisclosed fee on 29th August 2012. He signed a two-year deal, with the option for a third, at Carrow Road.

Bunn joined Rovers from Northampton in 2008 but only made 15 appearances and had loan spells at Leicester City (3 appearances) and Sheffield United (32 appearances) in 2009 and 2010.

Bunn began his career at Spurs as a trainee but joined Northampton Town before he was offered a professional contract. After a loan spell at Kattering in 2004, he made his first team debut in a 3–0 victory over Queens Park Rangers in the first round of the League Cup in August 2005. He was given his league debut by then-manager John Gorman against Nottingham Forest in August 2006. He made 90 appearances before signing for Blackburn on 29th August 2008 for a sum reported to be £1million.

Bunn made his Norwich debut in the 1-0 win over Doncaster Rovers in the Capital One Cup on 26th September 2012. His second appearance was on 31st October 2012 against Spurs in the same competition, which City won 2-1 with Bunn saving a late penalty to ensure City's progress to the next round. He later became Norwich;s first choice keeper following injury to John Ruddy. He ended up making 26 appearances for Norwich as they avoided relegation and eventually finished 11th in the Premier League.

Bunn made a further five appearances in the 2013/14 season, all in cup competitions.

On 16th January 2015, Bunn was supposedly told that he was free to leave Norwich to find further first team opportunities by new manager Alex Neil. “Mark has been a bit frustrated he has not had any game-time. I have spoken to him and made him aware if he can find himself a club then he can go,” said the City boss. “He wants to play football and he is not going to get that here and I am not in the habit of trying to hamper a boy’s career. He is here at the moment, he is training hard and he is a good lad but if he finds himself something then he is free to get first team football. I think Declan is a great back-up. Obviously John is the number one and he is a fantastic goalkeeper and we have Remi (Matthews) below that so we are well-covered.”

Bunn didn't play any games for Norwich during 2014/15 and was released at the end of the season

Although heavily linked with Bristol City at the beginning of July 2015. Bunn signed for Aston Villa on 9th July 2015 on a two year contract. He is expected to provide cover now that Shay Given had joined Stoke. Bunn made nine appearances as Villa struggled in the Premier League and were eventually relegated on 16th April 2016.

On 1st June 2019, Bunn was released by Aston Villa. He had made 21 appearances for Villa.

On leaving Villa, he set up his own coaching academy working with non-league Lutterworth Town and joined Cambridge in a coaching role. He left Cambridge in October 2021

Bunn is eligible to play for the Republic of Ireland through his father and grandmother. Bunn has expressed a strong desire to play for Ireland, but was not called up to the Irish team