The 19-year-old Campos Racing driver entered the decisive final round level on points with British rival Freddie Slater after being forced to chase the championship leader during the earlier stages of the season.
Ugochukwu kept his composure when it mattered most, avoiding trouble and finishing second to Tuukka Taponen of Finland to claim the title with 159 points.
His final tally left him 14 points clear of Slater, who finished the season as runner-up on 145 points.
Formula 1 confirmed Ugochukwu’s historic achievement in a post on its X handle on Sunday.
Calm Finish Secures Championship
With the championship finely poised before the final race, Ugochukwu needed to avoid unnecessary risks in Madrid.
Taponen made the perfect start from pole position, maintaining the lead through Turn 1 and controlling the gap to Ugochukwu behind him.
A late Safety Car intervention briefly threatened to alter the complexion of the race, setting up a dramatic final-lap sprint.
However, Taponen held his nerve to remain ahead and secure his maiden Formula 3 victory, while Ugochukwu crossed the line in second to complete his championship triumph.
Pedro Clerot finished third, while Slater could manage only eighth place, a result that ultimately ended his title hopes.
Reflecting on his approach to the decisive race, Ugochukwu said the team had prioritised avoiding mistakes rather than taking unnecessary risks.
“We knew we just had to keep it clean to clinch the title, and that’s what we did. No mistakes, brought it home and super pleased.”
Historic Achievement
Ugochukwu’s championship adds another significant milestone to his rapidly developing motorsport career and makes him the first American driver to capture the Formula 3 crown.
Born and raised in New York City, the teenager is the son of Nigerian fashion model Oluchi Onweagba and her Italian husband.
His success also places him in distinguished company, following previous Formula 3 champions such as Oscar Piastri and Gabriel Bortoleto.
Both Piastri and Bortoleto have subsequently progressed to Formula One, with Piastri racing for McLaren and Bortoleto competing for Audi.
Ugochukwu will now look to build on his Formula 3 success as he continues his progression through the highly competitive single-seater racing ladder.
Formula 3 sits one level below Formula 2, with the series regarded as an important stage for young drivers seeking to establish themselves before making the step up to Formula One.
For Ugochukwu, however, the 2026 season has already delivered a landmark achievement — a historic championship that further strengthens his credentials as one of America's most promising young racing talents.