Beginning his career in the youth academy of Norwich City, he left the club at the age of 15 in 2006, eventually moving onto Cambridge United, making his first-team debut in 2009. During his tenure with the side, he made 56 league appearances, 35 of which were from the substitutes' bench. He spent some time on loan at Conference North side Bishop's Stortford, scoring twice in six appearances.
He moved onto city rivals Cambridge City ahead of the 2013–14 season, a drop of two divisions into the Southern League Premier Division. He was prolific at this level, scoring 45 goals in 42 games as the Lilywhites finished 3rd. They were ultimately unsuccessful in their play-off campaign, and following interest from various Football League outfits, Marriott moved onto Stevenage for an undisclosed five-figure fee in July 2014.
Stevenage
After a successful pre-season campaign that saw him score five goals, including a hat-trick against Chesham United, Marriott made his Football League bow in a League Two game against Hartlepool United, which Stevenage won 1–0.
In June 2016 it was announced that Marriott would join Lincoln City as their 4th summer signing when his contract expired at Stevenage. He scored on his competitive debut for Lincoln against Woking as the Imps ran out 3-1 winners. He was part of the team that won the National League for the Imps in 2016/17. He also played an important role in their famous run to the FA Cupquarter final that season, including the crucial assist against Ipswich in round 3 and an appearance against Arsenal in the quarter final.
After helping Lincoln to gain promotion to the Football League, Marriott decided to drop down to the Southern Premier & signed for Royston Town. Marriott scored 31 goals in 43 appearances for the Crows, helping them to finish 7th in the league table only just missing out on a place in the play-offs.
Marriott signed for Southern League Premier Central side King's Lynn Town on 9 October 2018. Despite only joining the Norfolk club in October, Marriott went on to secure the Southern Premier Central LeagueGolden Boot by scoring 24 league goals forThe Linnets, which helped them finish as league runners up and qualify for the end of season play offs. Marriott's goalscoring form continued in the play offs with two goals in the Central Premier Final victory over Alvechurch. He then netted a late equalizer from the penalty spot in the Super Play Off against Warrington Town which took the game to extra time. King's Lynn went on to win that game and secure promotion to National League North. Despite King's Lynn being tipped to struggle in National League North, they sat top of the division at Christmas. Marriott's goalscoring form had seen him hit 21 league goals in the opening 20 games. His goal against Gateshead on 30 November 2019 was his 50th for King's Lynn Town, in just 61 games.
