Watkins started his career as a youth player at Swansea City but was released and he joined Cheltenham Town in 2008. On 9 August 2008, he made his first senior appearance for the club, playing in the last ten minutes of the 4–2 defeat at Northampton Town. In doing so, he became Cheltenham Town's youngest ever league player. He scored his first professional goal after coming on as a substitute against Northampton in the 2009–10 season. In September 2010, Watkins joined Conference National side Bath City on loan. He subsequently signed for Bath on a permanent basis in January 2011 after his successful loan spell. At the start of the 2012–13 season, Watkins signed a one-year deal at Hereford United. Watkins enjoyed a successful start to his Hereford career by winning a 'Player of the Month' award in his first month at the club. He ultimately played 34 league games and scored five goals in his season at Hereford. In June 2013 it was announced that Watkins would be joining Inverness Caledonian Thistle for the 2013–2014 season. He made his Scottish Premiership debut at Celtic Park on 24 August, coming on as a substitute in a 2–2 draw with Celtic. On 30 May 2015, he opened the scoring for Inverness in the Scottish Cup Final at Hampden Park, as the club secured a 2–1 victory against Falkirk. During Marley's time at Inverness Caledonian Thistle, the club finished in the top 3 to qualify for Europe for the first time in their history, got to the final of the Scottish League Cup and won football's oldest cup competition, the Scottish Cup. Marley scored and assisted one other in the final to help Inverness lift the cup. On 5 June 2015, Watkins signed for League One club Barnsley. In his first season with Barnsley, the club won the Johnstone's Paint Trophy against Oxford, and won promotion via the play offs to gain promotion to the Championship. Marley scored 8 and got 9 assists in 42 games during his debut season with Barnsley. Additionally, Watkins scored in his Championship debut against Ipswich and assisted another with Barnsley losing the game, 4–2. On 1 June 2017, Watkins signed for Championship club Norwich City on a free transfer. He joined the club on 1 July. He scored his first goal for Norwich in an EFL Cup tie against Charlton Athletic on 22 August 2017. On 15 June 2018, after one season at Norwich City, Watkins signed for fellow Championship side Bristol City for a fee of £1 million. The move reunited him with Lee Johnson, his manager at Barnsley.
International career
Watkins was born in England, and is of Welsh and French descent. Watkins was called up to the Wales national football team on 25 May 2017 for a match against Serbia on 11 June 2017. He made his debut for the side on 14 November 2017 as a substitute during a 1–1 draw with Panama.
