The 23-year-old replaces Valtteri Bottas as Hamilton’s new teammate having signed a long-term deal to form a mouth-watering all-British line-up at Mercedes. 

Before the start of the 2021 season, Hamilton penned a new two-year contract extension with Mercedes to commit his future in F1 until at least the end of 2022. 

Russell’s promotion to the Mercedes works team follows a number of impressive displays in an uncompetitive Williams since making his F1 debut in 2019. 

He claimed his first F1 podium in his 50th race at this year’s abandoned Belgian Grand Prix, finishing second to Red Bull’s Max Verstappen after securing Williams’ first front-row start in four years with one of the great qualifying laps in wet conditions. 

Russell, who won back-to-back GP3 and Formula 2 titles as a Mercedes junior in 2017 and 2018, has long been considered as a potential future world champion by the German marquee. 

His eventual graduation to race-winning machinery has long seemed inevitable and Russell’s prospects were boosted by an impressive debut for Mercedes at last year’s Sakhir Grand Prix when he stood in for Hamilton after the world champion contracted COVID-19. 

Russell came agonisingly close to a stunning maiden F1 win at the first attempt with Mercedes having outperformed Bottas in the race, only for a botched pit stop to cruelly end his hopes. 

Following his departure from Mercedes at the end of the season, Bottas will join Alfa Romeo on a “multi-year” deal to replace the retiring Kimi Raikkonen

Red Bull reserve Alex Albon and Mercedes' Formula E world champion Nyck de Vries are among the candidates to have been linked with the vacant Williams seat.