Steiner served as Haas team chief from its inception in 2016 until last winter, when his contract wasn't renewed after the struggling outfit finished last in the 2023 constructors' championship.
Exclusive: Steiner opens up on what really happened at the Haas F1 team
But the 58-year-old Italian went straight back into the paddock in Bahrain as an analyst for Sky Germany, and at last weekend's Australian Grand Prix he conducted the top three interviews.
Now, Steiner will also act as an ambassador for the upcoming Miami Grand Prix in May, helping to promote one of the championship's most recent additions to the calendar.
“I’m excited to serve as an Ambassador for the Miami Grand Prix, which has become one of my favourite races of the year,” said Steiner.
“I’ve seen first-hand the incredible growth Formula 1 has had in the United States and it has so much potential to continue growing, especially with races like Miami as part of the circuit.
"The event, which reflects the bold vision of the organisers, pairs American spectacle and F1 racing with a vibrant atmosphere at the track and throughout the city itself."
Steiner, who has been living in the United States for two decades and has a composites business there, has become a household name thanks to his colourful appearances on F1 Netflix series Drive to Survive.
He now looks set to stay a figurehead for the series even without an active role in one of the teams.
“Guenther has become a household name with F1 fans of all ages and is a perfect ambassador for our race,” said Miami GP president Tyler Epp. "He embodies the competitive spirit of the sport and has a clear vision of what F1 in America can be.
"Having someone with his experience, reputation and candour attached to our event will undoubtedly add to the excitement and elevate race weekend to a new level."
In a recent column for F1.com, Steiner said he has enjoyed his time away from active duty in F1, but doesn't rule out a return to a leadership role if the opportunity is right.
"Life has been good since I left Haas ahead of this season," he wrote. "These last few weeks are the first time I’ve switched off from F1 for around a decade. This time has been good for me.
"The longer time goes on, the more I can see that I stayed at Haas too long.
"I would come back to F1 in the future, but it needs to be the right project, done right."
