Born in Bristol, Jacob started his football journey with hometown Bristol City. Staying with the Robins until 2013, a 14-year-old Maddox then transferred to Premier League giants Chelsea, where he has remained ever since.
In his 6 years at Stamford Bridge, he has enjoyed plenty of successes at youth level.
Jacob came on as a substitute in both legs of the 2015-16 FA Youth Cup final win over Manchester City, before repeating the feat a year later, playing the full match of both legs in a 2016-17 FA Youth Cup final win.
He was also a member of England's 2017 UEFA Under-19 European Championship squad as the Young Lions lifted the trophy in Georgia, defeating Portugal 2-1 in the final.
Maddox secured his first senior match time in 2018-19, spending the season on loan at League Two Cheltenham Town. During his time at Whaddon Road, he made 44 appearances and scored 4 goals, earning him the Young Player of the Season award at the end of his first senior campaign.
On 8th August 2019, it was announced that Maddox had signed for Tranmere Rovers on a season-long loan that will see him join Micky Mellon's League One squad for 2019-20.
Interesting Fact: Jacob played in both of Cheltenham's matches against Tranmere in 2018-19, losing 1-0 at Prenton Park and 1-3 at Whaddon Road.