Carlos Sainz intends to continue Williams' upward trajectory in Formula One after enjoying a positive debut season alongside Alex Albon in 2025. 

Sainz made the move to Williams from Ferrari ahead of last season after being replaced by seven-time world champion Lewis Hamilton, who switched from Mercedes. 

The Spaniard finished ninth in the drivers' championship with 64 points after struggling early on in the campaign, having retired from two of the first four races. 

He recorded his first points finish at the Chinese Grand Prix and would go on to finish in the top 10 nine more times in 2025, placing just nine points behind team-mate Albon. 

Sainz stood on the podium for the first time for Williams in Azerbaijan in September, four years and 23 days since the British team last achieved the feat with George Russell. 

They finished fifth in the constructors' championship on 137 points and ahead of the 2026 season, which will see widespread regulation changes, Sainz is optimistic.

"The team is on an upward trajectory, and it's fundamental to continue that trajectory," Sainz said. 

"It's important to keep showing progress, to not stall that progress that we are showing. 

"Having said that, with such a big change of regulations, that progress might look different next year, because it's going to be so unpredictable to know where everyone's going to be.

"But I trust what the team is doing, I trust all the efforts that we've been putting into next year's car, through all the simulator sessions and all the development work.

"I'm feeling positive. I'm relatively happy and confident about it, but with the impossibility to say more than, 'I don't know where we're going to be'".

FW47, you really did spoil us pic.twitter.com/pmXq7tPZ4F

— Atlassian Williams Racing (@WilliamsF1) December 18, 2025

Many questioned Sainz's decision to join Williams, with the British team known for being the backmarkers on the grid before appointing James Vowles as their team principal in 2023. 

The likes of Alpine and Sauber were also interested in the 31-year-old's signature, but he opted to sign for Williams due to their long-term goal of returning to the front of the grid. 

And, in some respects, you could say Sainz had a better season than Hamilton, given the Brit failed to register a podium finish for the first time in his F1 career. 

But it was not all plain sailing for Sainz, who added: "If you told me at the beginning of the year that there was going to be fifth position for Williams at the end of the championship, a good step forward, closing the gap to the top teams, and a couple of podiums, I would have taken it. 

"It's been a good year overall.

"Also, when I signed with Williams in the summer of 2024, if I had told people that I'm joining them because these results are going to happen, they wouldn't have fully believed me. I have the results now to back why I chose this team – a vindication."