Career
Brown played for West Bromwich Albion"s academy and under-21 teams before making his senior debut in 2013. Since signing for Chelsea, he has played for their under-21 team Brown has represented England at under-16, under-17 and under-19 levels.
West Bromwich Albion
On 2 March 2013 Brown made the bench for the first time in an away league match against Chelsea, an unused substitute as West Brom lost 1–0.
On 6 April 2013, again Brown made the bench and was again not used as West Brom lost 2–1 to Arsenal at The Hawthorns. Brown made his debut for West Bromwich Albion on 4 May 2013 in a 3–2 home Premier League defeat to Wigan Athletic, replacing Youssouf Mulumbu for the last four minutes and becoming the second-youngest player in Premier League history at the age of 16 years and 117 days.
On 8 July 2013, West Bromwich Albion rejected an offer for Brown from Chelsea. Later that month, Chelsea confirmed that they had signed Brown, with compensation between the clubs reportedly set to be decided by a tribunal.
After Brown left the club West Brom"s chairman considered scrapping the club"s category one development academy as the EPPP rules Chelsea used to sign Brown meant that the club were losing their best prospects for nominal fees that failed to cover the cost of running an academy.
Chelsea
= 2014-2015 season Brown scored his first goals for the Chelsea first team on 16 July 2014 in a 5–0 pre-season friendly victory over Wycombe Wanderers. On 29 July 2014, Chelsea manager José Mourinho said that he should be blamed if Brown were not to become a senior England international under his management. On 28 October, Brown made the Chelsea bench for the first time in a competitive fixture, but was an unused substitute as Chelsea beat Shrewsbury Town 2–1 to advance into quarter-finals of the League Cup.
On 31 January 2015, Brown made the Chelsea bench against current league title holders, Manchester City, but was again an unused substitute as Chelsea drew 1–1.
Three days after the match, on 3 February, Brown was promoted into Mourinho"s first team squad alongside fellow teenager Ruben Loftus-Cheek. On 12 April, Brown was named on the first team bench for the third time that season for a West London derby against Queens Park Rangers.
Less than 24 hours later he captained Chelsea U19 in the final of the 2014-2015 Union of European Football Associations Youth League against Shakhtar Donetsk in Switzerland and put in a man of the match performance scoring 2 goals to help Chelsea take the title. On 18 May, Brown made his Chelsea debut, coming off the bench for Loïc Rémy for the final eleven minutes of a 3–0 defeat at his former club West Bromwich Albion.
= Loan to Vitesse On 10 July 2015, Chelsea agreed to a deal that will see Brown go on loan to Dutch side Vitesse Arnhem along with new signing Nathan.
He made his competitive debut 13 days later in a Union of European Football Associations Europa League third qualifying round first leg against Southampton at Saint Mary"s, playing the full 90 minutes of a 3–0 defeat. On 6 March 2016, Brown scored his first senior goal, giving Vitesse the lead in the 34th minute in their 2–1 victory over Roda JC Kerkrade.