Forward Marley Watkins signed for Norwich on a free transfer from Barnsley on 1st June 2017. This will be completed on 1st July 2017.

Although born in London, Watkins grew up in South Wales and joined Swansea as a youth team player in 1999. He was released in 2007 and joined Cheltenham Town in 2008. On 9th August 2008, he made his first senior appearance for the club, playing in the last ten minutes of the 4–2 defeat at Northampton. In doing so, he became Cheltenham Town's youngest ever league player.

In September 2010, he joined non-league Bath City on loan which was made permanent in January 2011.He spent the following season at Hereford 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, jhe joined Scottish side Inverness Caledonian Thislte, making his debut in a 2-2 draw at Celtic. 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. During this time, he was placed on standby for the Welsh international team.

On 5th June 2015, he signed for Barnsley. n his first season with Barnsley, the club won the Johnstone Paint Trophy against Oxford, and won promotion via the play offs to gain promotion to the Championship. He had a decent season in 2016/17 scoring 10 goals in 45 appearances, primarily in the Championship.

He made his Norwich debut in the 1-1 draw away to Fulham on the opening day of the 2017/18 season (5th August 2017). He scored his first goal for Norwich in the 4-1 win in the League Cup against Charlton on 22nd August 2017.

Watkins made his debut for Wales in the 1-1 draw with Panama on 14th November 2017. He came on as a 70th minute sunstitute.

On 15th June 2018, Watkins was sold to Bristol City for a fee of just over £1million. He is reunited with Bristol City manager Lee Johnson, who signed Watkins in 2015 when he was Barnsley boss, after the two forged a strong working relationship during their time in Yorkshire.

Marley returned to Scotland on 22nd August 2020 signing for Aberdeen on loan until January 2021. With strikers Sam Cosgrove, Curtis Main and Ryan Edmondson all out injured, Watkins will provide cover up front for Aberdeen. He had scored three times in 27 appearances for Bristol City. He played 13 games for Aberdeen, scoring twice.

On 14th May 2021 Bristol City announced that Watkins would be leaving the club in the summer of 2021.He had played 29 games for the Robins, scoring three goals.

In July 2021 Marley joined Cardiff City on trial, playing in their 5-0 win over Bath City on 10th July 2021. He signed a one month contract with Cardiff on 10th August 2021 and made his full debut the same day, scoring twice in a 3-2 League Cup win over Sutton United. However Cardiff announced that they would not be extending the contract making this his sole appearance.

On 26th August 2021 he signed a two year contract with Aberdeen. Manager Stephen Glass said: “I’m delighted Marley has chosen to return to the Club. In his previous spell at Aberdeen his influence on the team was enormous and we are looking forward to having him back in a red jersey. I expect the fans will be delighted to see him back with the club."

Watkins was released by Aberdeen on 13th June 2023. The following month he joined Oxford United on trial. Asked about trialists at the club, Oxford manager Liam Manning responded: “There’s only one in training with us at the moment, who we had an approach from and we decided to follow that up. It’s something we wouldn’t rule out completely, we currently carry quite big numbers so what it can’t be is at the expense of someone that we’ve got in. I don’t like wasting people’s time. If we know there’s no potential to be signed or it’s not a position we’re looking to fill, then we wouldn’t do it.”

On 21st July 2023 he signed a one year contract with  Scottish Premiership club Kilmarnock, reuniting with former Aberdeen manager Derek McInnes.