Zhou began karting at age eight in China before moving to Sheffield in 2012 to pursue a more competitive environment, attending Westbourne School. In 2013 he won both the Super 1 National Rotax Max Junior Championship and the Rotax Max Euro Challenge with the Sheffield-based Strawberry Racing team. He made his sole appearance in the Karting World Championship that year alongside Lando Norris and Jehan Daruvala for Ricky Flynn Motorsport.
Zhou joined Prema Powerteam for the 2015 Italian F4 Championship, winning three consecutive races at Monza's Round 2 and finishing as vice-champion and best rookie. He progressed to the FIA Formula 3 European Championship in 2016 with Motopark, finishing 13th. He returned to Prema for 2017, improving to eighth with five podiums, then stayed for a third F3 season in 2018, recording three poles and two wins while finishing eighth overall.
In 2019 Zhou moved to the FIA Formula 2 Championship with UNI-Virtuosi, finishing seventh and winning the Anthoine Hubert Award as the highest-finishing rookie. He continued with Virtuosi in 2020, taking his first F2 victory at Sochi. In 2021 he secured four wins and nine podiums to finish third in the championship, including victories in Bahrain, Monaco and Britain. During the 2020–21 off-season he won the F3 Asian Championship with Prema, taking four wins and five poles.
Zhou was a member of the Ferrari Driver Academy from 2014 to 2018 and then the Alpine (Renault) Academy from 2019 to 2021. He served as a development and test driver for Renault and Alpine during those years, making his Formula One race weekend debut in FP1 at the 2021 Austrian Grand Prix in an Alpine A521.
Zhou signed a contract with Alfa Romeo for 2022, partnering Valtteri Bottas and becoming the first Chinese driver to start a Formula One World Championship race. He chose the number 24 in tribute to basketball player Kobe Bryant. On debut at the Bahrain Grand Prix he qualified fifteenth and recovered from a poor start to finish tenth, scoring a point.
At the British Grand Prix, Zhou was involved in a severe first-lap collision with George Russell that sent his car flipping upside-down and sliding across the track, gravel and barriers into the catch fence. He was extracted and declared fit, later stating that the halo had saved his life.
He scored points a second time with eighth at the Canadian Grand Prix and added his first career fastest lap at Japan. He ended the season eighteenth with six points.
Zhou remained at the rebranded Alfa Romeo alongside Bottas for 2023. He scored ninth at the Australian Grand Prix from seventeenth on the grid and added two more points-scoring finishes in Spain and Qatar. A strong performance at Hungary, where he qualified fifth — his best Formula One qualifying result — ended in a first-corner collision. He finished eighteenth again with six points.
Following Alfa Romeo's exit as title partner, the team rebranded to Stake F1 Team Kick Sauber. Zhou scored Sauber's only points of the season at the Qatar Grand Prix, qualifying twelfth and finishing eighth after two safety car periods. He was voted Driver of the Day. He also completed his first home race when the Chinese Grand Prix returned to Shanghai for the first time since 2019. Zhou left the team at the end of 2024 when Nico Hülkenberg and Gabriel Bortoleto were signed ahead of Audi's eventual takeover.
Zhou joined Ferrari as a reserve driver for 2025, but it was announced at the start of 2026 that he would not continue in the role. He subsequently joined Cadillac as a reserve driver for the team's inaugural Formula One season in 2026.
Zhou Guanyu holds a unique place in motorsport history as the only Chinese driver to compete in Formula One. His career at Alfa Romeo and Sauber was constrained by machinery that was consistently uncompetitive, making meaningful comparison with peers difficult. The British Grand Prix crash of 2022, which he survived largely because of the halo cockpit protection device, became one of the most widely cited examples of the halo's life-saving function in the modern formula.