Look back on his career with The Blues in our gallery of pictures from his time at Fratton Park.
Ipswich Town teenage defender Matt Clarke joined Portsmouth on loan on August 3, 2015, after spending July on trial with The Blues. Here he is in action during a pre-season game against Gillingham with Bradley Dack chasing him down.
Matt Clarke made his debut during Pompey's first game of the League Two 2015/16 season on August 8, 2015, against Dagenham & Redbridge at Fratton Park.
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Matt Clarke of Portsmouth tries to tackle Simon Dawkins of Derby County during the Capital One Cup First Round match between Portsmouth v Derby County at Fratton Park on August 12, 2015
Matt Clarke in action against Northampton in December 2015, his loan was due to come to an end at the start of 2016, however he committed his loan future to The Blues and signed until the end of the season.
Matt Clarke got his first goal of his Pompey career during the Sky Bet League 2 match between Portsmouth and Crawley Town at Fratton Park, Portsmouth, England on January 2, 2016.
In the summer of 2016, Clarke made his loan switch to Portsmouth from Ipswich permanent as part of swap deal that saw Adam Webster head to Portman Road.
Throughout the 2016/17 League Two season Matt Clarke formed a defensive partnership with Christian Burgess, which helped Pompey to the best defensive record in the league that season.
Matt Clarke bagged his second goal for Pompey during a 2-0 win over Accrington Stanley at Fratton Park on February 11, 2017.
Pompey players, including Matt Clarke (back row) celebrate winning the League Two title after a dramatic final day 6-1 win over Cheltenham Town at Fratton Park on May 6, 2017.
Clarke certainly enjoyed scoring against Crawley Town in his Pompey career - here he is celebrating after scoring against them in Checkatrade Trophy on Tuesday, October 3, 2017 at Fratton Park
Clarke opened his League One goal account against Bury at Fratton Park on December 16, 2017.
Matt Clarke celebrates scoring a goal at MK Dons on February 10, 2018, doubling his League One tally for the season
Pompey defender Matt Clarke was named The News/Sports Mail player of the season for the 2017-18 campaign after an impressive year.
The defender opened the scoring in Pompey's run to Checkatrade Trophy glory, scoring the first goal in Pompey's win against Gillingham FC at Fratton Park on September 4, 2018
Clarke celebrates scoring during Pompey's match at Rochdale September 29, 2018, the Blue won 3-1 and went back to the top of League One.
Matt Clarke's goal during a 2-2 draw with Burton Albion on October 23, 2018, helped Pompey keep up momentum at the top of the table
Matt Clarke was part of the Pompey team that lifted the Checkatrade Trophy for the first time in the club's history
Matt Clarke scored the late winner as Pompey beat Burton Albion 2-1 at the Pirelli Stadium on April 19, 2019.
Matt Clarke was named the player of the season for the second time and was given the trophy before the final league home game against Accrington Stanley
Matt Clarke does a lap of appreciation following his final league home game against Accrington Stanley on May 4, 2019.
Matt Clarke and his Pompey teammates look dejected after Sunderland's Chris Maguire scored the only goal in first leg of League One play-off
Pompey's season and Matt Clarke's career at Fratton Park came to a heartbreaking end as the blues crashed out of play-offs with a 0-0 draw at home against Sunderland.
After months of speculation, Matt Clarke has sealed his move to Premier League side Brighton. Leaving Pompey on June 21, 2019.