Fenwick played football for St. Bede's School, where he was in the six-a-side team that won the ISFA National Six-a-Side Tournament. He then played for the Lewes U18 team in a side that included Solly March, scoring 18 times in 11 games and earning a trial at Crystal Palace where he scored for their youth team in a match against Norwich City.[2][3]
On 1 March 2012, he signed for Crystal Palace as a second year scholar[4] and in August 2012 played for the first team in a pre-season friendly against Aldershot Town,[5]
although his manager Dougie Freedman said he was unlikely to make it into the first team that season.[6] Fenwick played 12 games for Palace's Under-21 team in the 2012–13 season, scoring three goals, with four assists. He also played on loan at Eastbourne Borough.[7] In June 2013, Fenwick was one of six academy players released by Palace following their promotion to the Premier League.[8]
Fenwick spent a short time training with Cardiff City and played 5 games for the U21 side. He then signed for Lewes, before joining Peacehaven & Telscombe in February 2015,[9] being sent off on his debut against Lewes.[10]
Fenwick joined Torquay United on 23 July 2015 having played with them in pre-season.[11] He was released by Torquay in December 2015[12] and then spent a short time at Truro City, appearing once in the FA Trophy against Macclesfield Town,[13][14] before joining Selkirk of the Scottish Football Lowland League in February 2016.[15]
Fenwick started the 2017-18 pre-season back in East Sussex on trial at Brighton-based National League South side Whitehawk, earning a deal after scoring a 35-yard screamer against Burgess Hill Town.[16][17] After starting six games and making four appearances from the bench, Fenwick asked to be released from his contract after Steve King took over as manager.[18]
In March 2018, Fenwick joined Danish 2nd Division side FC Sydvest.[19]
On 1 February 2019, Fenwick joined fellow Danish 2nd Division Jammerbugt.[20]
On 28 July 2020, Fenwick signed for Brønshøj on a one-year deal.[21] After one season, he left to join Hillerød Fodbold.[22]
