Born in Kaduna, Nigeria to a Hongkongese father and a Nigerian mother, Brian started to have professional football training in Kaduna Football Academy at the age of 5. In 2004, he moved from Nigeria to Hong Kong. After moving in Hong Kong, Brian trained and played for the youth football team of HKFC Soccer Section, Yau Tsim Mong and Hong Kong Rangers. Brian completed his high school education at :zh:官立嘉道理爵士中學（西九龍）|Sir Ellis Kadoorie Secondary School. Brian was also the 200 meter dash champion for 4 years running at the Hong Kong Schools Sports Federation Athletics Meet. In 2010, Fok played as an amateur for Rangers in Hong Kong Second Division. In 2011, Brian rejoined Rangers and made his professional debut in February 2012 as a late substitute against Tai Po. On 20 May 2012, Brian started as line-up against Kitchee, and played for the whole match which they lost 1–4. In 2012, Fok studied in England at the Brooke House College Football Academy for 1-year professional football training. In 2013, Brian moved to train and play for Jamie Lawrence Football Academy. In 2014, Fok went for trial at Chinese Super League club Shanghai Shenhua, going on to sign a three-year deal with the club. In December 2014, Fok joined Spanish Club CF Cracks on a half season loan, played 6 matches for the club as a centre back and also as a centre forward. In February 2016, Shanghai Shenhua allowed Brian to join Berceni on a half season loan to gain first team experience. In August 2016, Fok joined Azerbaijan Premier League club AZAL PFK on a half season loan deal, making his debut as a substitute in a 3–0 defeat to Gabala on 19 September 2016. The appearance meant Fok was the first Hong Kong player to play in Azerbaijan, and the 4th Hong Kong player to play in Europe. On 6 November 2016, Brian started and played full match against Gabala, the match ended at a draw 0:0. Fok left AZAL on 24 December 2016 following the conclusion of his loan. On 21 February 2018, Fok joined Uruguayan Segunda División club Juventud on a half season loan. On 13 August 2018, Fok signed a 2 years deal and transferred to LigaPro club Académico de Viseu. On 15 July 2019, Fok returned to Hong Kong and signed for Hong Kong Premier League club Kitchee. He played his first game for the club on 10 September 2019 against Lee Man FC in a senior shield match, in which Kitchen was beaten 5-1 and Fok was substituted in the 2nd half.
International career
Since Feb 2011, Brian have been playing for different age groups of Hong Kong National football youth team.
