“We're all delighted to continue our relationship with Pietro Fittipaldi,” said team principal Guenther Steiner.
“The role of test and reserve driver means you might be called up to drive at very short notice and that turned out to be the case for Pietro in Bahrain at the end of 2020.
“Despite the demands of driving with little time to prepare, he undoubtedly did a solid job for us – not least as he hadn't even tested the VF-20.
“He didn't get caught up in the moment, he proved patient and ultimately, he did what he was asked to do – he brought the car home in Bahrain and Abu Dhabi.
“That first-hand race experience will only serve to add value in terms of what he brings to the team in his role this season.
“We look forward to working with Pietro and having him with us again throughout the year.”
Fittipaldi said, “I'm very happy to be able to continue into my third year with Haas F1 Team.
“I'm grateful to Gene [Haas, owner] and Guenther for the opportunity once again.
“I've been working with the engineers now for a couple of years and I really feel like it's a big family at Haas. It's a great pleasure for me to be able to continue working with the team.
“With the two races I ran last year, it just helped me gain even more experience, and I'm sure that's going to help me be able to contribute more to the team as a result.
“I'm really looking forward to the new season and I'm just really excited to be continuing my relationship with Haas and being with them again in Bahrain in March.”
Haas will field an all-new race driver duo of Mick Schumacher and Nikita Mazepin this year.