Berrett was born in Halifax, West Yorkshire. He is a product of the Huddersfield Town academy, and made his first-team debut at Boundary Park when he came on as a 69th-minute substitute in the 1–1 draw with Oldham Athletic in April 2007. He signed a professional contract with Huddersfield on 5 July 2007. Berrett made his full debut in Huddersfield's third round FA Cup win over Premier League team Birmingham City on 5 January 2008. The following week he made his first full league debut in Huddersfield's 3–1 defeat at home to Gillingham. His first goal for Hudersifled came in the 3–2 win against Bristol Rovers at the Memorial Stadium on 22 March 2008. On 13 May 2008, he signed a new two-year deal at the Galpharm Stadium. On 6 August 2008, he scored to give Huddersfield the lead in their centenary match against Arsenal at the Galpharm Stadium, in which they lost 2–1. Following Stan Ternent's departure as Huddersfield manager, caretaker boss Gerry Murphy deployed Berrett in a sweeper role as part of a back five. Then, following Lee Clark's decision to revert to the 4–4–2 formation, Berrett found himself out of the team again, but following an illness to Anthony Pilkington, just before the match against Crewe Alexandra in February 2009, he got back in the starting line-up and scored a goal, but Huddersfield lost the match 3–1. He signed a contract extension which would keep him at the club until 2012. Berrett made nine appearances only stating two with seven coming off the bench in the 2009–10 season. He made his first appearances of the season coming on as a 56th-minute substitute for Lee Peltier in Huddersfield's League Cup second round tie away at Newcastle United. His first start of the season came in Huddersfield's 1–0 away defeat at Colchester United on 3 October 2009. His first home appearance did not come until 12 December 2009, when he came on as a 90th-minute substitute in Huddersfield's 2–1 home win over Gillingham.
After being put on the transfer list by manager Lee Clark, Berrett left Huddersfield to sign for fellow League One club Carlisle United on a free transfer on 6 July 2010. On 11 June it was confirmed that Berrett would sign a new two-year deal with Carlisle.
On 3 July 2014, Berrett signed for Yeovil Town on a two-year contract after he failed to agree a new contract at Carlisle. After an injury-plagued start to the season Berrett made 32 appearances for Yeovil scoring once, the winner against Swindon Town in April 2015. At the end of the season, following Yeovil's relegation into League Two, Berrett was one of four players offered a contract termination by new manager Paul Sturrock.
Barrett signed for League Two club Grimsby Town on 30 June 2016 on a two-year contract for an undisclosed fee. He was released by Grimsby at the end of the 2017–18 season.
On 27 June 2019, Berrett signed with Grantham Town.
International career
On 7 February 2007, Berrett made his debut for the Republic of Ireland national under-18 team when starting their 0–0 home draw in a friendly with the Netherlands. He started their first two matches of the Four-Nations Tournament in Portugal, but was dropped for the final match, which the Republic of Ireland won to win the tournament. Berrett finished his under-18 career with three cap, all earned in 2007. Berrett debuted for the under-19 team in their 2–1 home win over Chile in a friendly on 7 August 2007. He earned five caps for the under-19s, from 2007 to 2008. He was called up to the under-21 team for the Intercontinental Cup in Malaysia, and made his debut with a start in a 3–1 win over Malaysia on 15 May 2008. Berrett was dropped for their second group match, before starting the draw in their final group match, which saw them knocked out of the tournament. He was capped five times by the under-21s, with all these appearances coming in 2008.
