The shock news was announced by the US-owned company on Wednesday in the wake of a dismal 2023 season that saw it finish 10th and last in the Constructors' World Championship.
Steiner's contract was up for renewal at the end of the year, and team owner Gene Haas chose not to extend it.
As previously reported, former coach Simone Resta has also left the team in a decision that precedes Steiner's departure.
Steiner, who formulated the plan for the Formula 1 team using Ferrari technology and then secured funding from machine tool manufacturer Haas to start the plan, appears to have paid the price for last year's poor performance.
It was no secret that at times there was tension between Steiner and Haas, and there were differences of opinion in the camp about which technical direction to follow, with the split of the old and new aero packages seen in the final two races of 2023 a clear general sign of the divergent views.
In essence, Steiner was demanding more investment in an attempt to keep up with competitors spending heavily on upgraded factory infrastructure, while Haas wanted to focus on more efficient use of the resources his team already had at its disposal.
Slipping to 10th is a major blow to the team's share of the Formula 1 prize fund, and means Haas has to commit to making a larger contribution to the ongoing budget for 2024 than it had expected, effectively leaving less margin. To invest in facilities.
Photography: Andy Hone / Motorsport pictures
Guenther Steiner, Team Principal, Haas Formula 1 Team
In stark contrast, the likes of Williams, Sauber and AlphaTauri have benefited from the additional capital expenditure allocations allowed by the FIA and have committed to additional spending in the run-up to the 2026 regulatory changes.
The team says Komatsu will be responsible for the team's strategy and on-track performance. In a statement, she noted that he will have a “brief to maximize the team's potential through employee empowerment, process structure and efficiency.”
Komatsu will be supported on the regulatory and commercial side by a new yet-to-be-appointed COO, who will focus on non-racing matters and will likely be based at the UK facility in Banbury.
Owner Haas has made it clear that his focus is on improving the team's performance.
“I would like to start by thanking Gunther Steiner for all his hard work over the past decade and wish him well for the future,” he said.
“Moving forward as an organization, it was clear that we needed to improve our performance on the right track. In appointing Ayao Komatsu as Team Manager, we have fundamentally placed engineering at the heart of our management.
Photo taken by: Motorsport pictures
Ayao Komatsu, chief engineer, Haas Formula 1 Team, at the team principals' press conference
“We have had some successes, but we have to be consistent in achieving results that help us achieve our broader goals as an organization. We need to be efficient with the resources we have, but improving our design and engineering capabilities is key to our success as a team.
“I'm looking forward to working with Iao and basically making sure we maximize our potential – this really reflects my desire to compete properly in Formula 1.”
Komatsu, who joined the Banbury team from Renault as chief race engineer in its first season in 2016, becomes the first Japanese team principal for the sport from a European team.
“I am naturally very excited to have the opportunity to be Team Principal at MoneyGram Haas F1 Team,” he said.
“Having been with the team since its debut in 2016, it is clear that I am passionately invested in its success in Formula 1. I look forward to leading our program and the various competitive processes internally to ensure we can build a structure that results in improved on-track performance.
“We are a performance-driven company. We have obviously not been competitive enough recently, which has been a source of frustration for all of us.
“We have amazing support from Jane and our various partners, and we want to reflect their enthusiasm with an improved, on-track product. We have a great team of people in Kannapolis, Banbury and Maranello, and I know together we can achieve the kind of results we are capable of.”
Photography: Eric Junius
Kevin Magnussen, Haas Formula 1 Team, Guenther Steiner, Haas Formula 1 Team Principal
Steiner has played a big role in raising the team's profile in recent years thanks to his appearance in Drive to Survive, making him well-known outside the Formula 1 paddock.
It remains to be seen what Haas' sponsors, including title backer MoneyGram, think about his departure.
Speaking to Motorsport.com last year, Moneygram CEO Alex Holmes explained that Steiner was an important part of the team's appeal.
“We saw Gunther's influence when we first met and went out to dinner,” he said.
“People would come to the table in the middle of dinner and want to take a picture of him, and they would get giddy to see him. And he's so funny and so real. He's like, 'I don't know what's going on!'”
“To see the star impact that he has, and how he shows that, that's who he is. And I think the honesty really comes through. And for us to also be able to associate our brand with his brand is very special.”
“Alcohol enthusiast. Twitter ninja. Tv lover. Falls down a lot. Hipster-friendly coffee geek.”