The 40-year-old Hamilton has instead opted to join Ferrari, in a blockbuster pairing between one of the most successful drivers in the sport's history, and the most successful and iconic outfit on the F1 grid.
Hamilton will be hoping to banish his last three seasons with Mercedes from his memory, and once again challenge for an unprecedented eighth world title with the Scuderia.
Lewis Hamilton has joined Ferrari for 2025 and beyondLewis Hamilton is a seven-time Formula 1 world champion
When will Hamilton make his Ferrari debut?
Hamilton has already conducted a number of private tests with his new Ferrari team, both at their Fiorano track, and at the Circuit de Barcelona-Catalunya alongside team-mate Charles Leclerc.
His official race debut with Ferrari, however, will not take place until March 16, at the season-opening Australian Grand Prix.
Now, the 16-time constructors' champions have taken to Instagram to celebrate a personal milestone for Hamilton at Ferrari, in relation to the F1 legend's iconic race number 44.
Hamilton has raced with this number since new rules entered the sport in 2014, and even declined the chance to use the number one when he was world champion, an option that Max Verstappen has taken up in the past few seasons.
The Brit has been at Ferrari for 44 days now, despite not having made his race debut yet, prompting a social media post from the team celebrating the feat.