Gelael started his racing career competing in 2012 in the Formula Pilota China where he finished his debut season as fourth overall. For the last round of the 2012 Formula Abarth Season at Monza, Sean raced for the team BVM.
Going into 2013, Sean competed alongside Formula 1 driver Antonio Giovinazzi for Double R Racing in the British Formula 3 season where he received his first podium in F3, claiming 3rd during the second race at Silverstone. On July 7th 2013, he made is debut in the Masters of Formula 3 but was forced to retire. Gelael also joined Double R Racing team to compete in the 2013 FIA European Formula 3 Championship season before moving to Carlin in 2014.
On May 10th 2014, he scored his first ever point in the championship by finishing 10th in Pau Grand Prix. He completed his 2014 season in 18th. Gelael continued his partnership with Carlin during the 2014 British Formula 3 Championship, the 2015 Formula Renault 3.5 Series and made his debut in to the GP2 Series alongside the team in Hungary where he finished 18th in the feature race and 20th in the sprint race. For his second season in GP2, Sean moved to compete full time with Campos Racing alongside team mate; Mitch Evans. He claimed his first podium in Spielberg, Austria where he finished 2nd to his team mate.
FIA Formula 2 Championship
Sean made his Formula 2 debut in 2017, joining Pertamina Arden team before racing for the Prema Racing team with Dutch driver, 2019 FIA F2 Champion, Nyck de Vries. He continued with Prema going into the 2019 season with 2018 FIA Formula 3 European Champion, Mick Schumacher. He lost the team battle and finished 17th in the drivers’ standings, scoring points in only five races.
For the 2020 season, Gelael has left Prema and joined the reigning FIA F2 team’s champion DAMS alongside team mate Dan Ticktum, who competed in the 2019 Super Formula Championship for only three races before being dropped by his team.