Born in Suffolk, Matt joined Ipswich Town’s academy as an under-7, spending 12 years in their youth ranks.

He penned a deal to become a scholar in 2013, making his professional debut the following year in a League Cup tie away at Crawley Town.

A month after his debut, Matt signed a two-year professional contract at the club and spent the following campaign on loan at Portsmouth, racking up 33 appearances on the south coast.

He joined Pompey on a permanent basis upon the end of his loan stint, as part of a swap deal with Adam Webster heading to Ipswich in the opposite direction, helping Paul Cook’s side record the meanest defensive record alongside ex-Boro centre-back Christian Burgess.

Scooping up both Player of the Season and Players' Player of the Season during the 2017/18 campaign, Matt cemented himself as one of the best defenders in the division with another Player of the Season award in 2018/19 before Premier League club Brighton came calling.

The Seagulls forked out a fee in excess of £3m to bring him to the Amex Stadium, with Matt immediately shipped out on loan to Derby County.

He claimed a third successive Player of the Year award while at Pride Park before returning on loan to aid them to Championship survival in the behind-closed-doors 2020/21 campaign.

Spending the following season on loan at West Bromwich Albion, Matt recorded a fourth Player of the Year honour at the Hawthorns before joining Boro in August 2022. 

Matt’s first season at the club was restricted to just six appearances due to a back injury. The defender's second season at the Riverside was more fruitful, with Matt making 24 appearances.

In the last away fixture of the season at Cardiff, the defender scored his first goal for the club after he was on the end of a dangerous Finn Azaz cross.