Bearman stood in for Carlos Sainz in Jeddah after the Spaniard was diagnosed with appendicitis.
Despite not driving the car until final practice – Sainz had driven on Friday – Bearman qualified 11th and finished seventh in the race.
Speaking at Silverstone on Thursday at the start of the British Grand Prix weekend, Bearman said he believed his performance in Jeddah had been a “major contributor” to securing his promotion to F1.
“It showed what I was capable of,” he said, “that the guys with less experience are not so far behind the normal cohort.”
He said he had known for a while that he was heading for the Haas seat in 2024 but that it was finally confirmed on Sunday after the Austrian Grand Prix.
“It was an emotional moment,” he said. “I’ve been working so hard for this, and the sacrifices I’ve had to make, I feel like they’ve paid off.”
Haas team principal Ayao Komatsu said: “It’s an exciting thing to be able to give a young driver as talented as Oliver Bearman his first full-time seat in Formula 1.
“He’s developed into an incredibly mature driver under the guidance of the Scuderia Ferrari driver academy and the world saw that for themselves when he was called in at the last minute to compete at the Saudi Arabian Grand Prix.”
Bearman said he had set himself no specific objectives for his debut full season next year but that he wanted to continuously improve through the year.
“I just want to be proud of my performances,” he said. “You know whether you’ve done a good job or not.”
And he said it was “amazing to think” that he would be racing against heroes such as Lewis Hamilton and Fernando Alonso, both of whom were complimentary of Bearman’s drive in Jeddah.
Bearman, who has been a member of the Ferrari driver academy since 2021, will join Lewis Hamilton, George Russell and Lando Norris, meaning 20% of the F1 grid will be British drivers next year.
In addition, Williams driver Alex Albon, who races under the Thai flag, was born in London and has dual Thai-British nationality.
“Oliver proved he was more than ready for the task, and we’ve seen that for ourselves, running him in the Haas cars in our first practice sessions over the past two seasons,” added Komatsu.
“We’re looking forward to further developing him as a driver and reaping the benefits of his talent – both inside and outside of the car.”