The Massachusetts native thanked her colleagues in a statement for their "wonderful love and support" over nearly three decades.
Sunita "Suni" Williams has announced her retirement from NASA.
Williams, 60, officially retired from the agency on Dec. 27, 2025, according to a press release shared by NASA on Tuesday, Jan. 20.
The Massachusetts native set "numerous human spaceflight records throughout her career," and made headlines beginning in 2024 when she and partner Butch Wilmore found themselves stuck in space for nine months.
In a statement addressing her retirement, Williams said she "had an amazing 27-year career at NASA" thanks to "the wonderful love and support" she received from her colleagues.
"It's been an incredible honor to have served in the Astronaut Office and have had the opportunity to fly in space three times," Williams said in her statement.
Williams called the people and science at NASA "truly awe-inspiring," and said she hopes to have helped set a solid foundation for those taking "bold" new steps toward exploring the moon and Mars at the agency.
"I am super excited for NASA and its partner agencies as we take these next steps, and I can't wait to watch the agency make history," she stated.
Williams launched into space for the first time in December 2006 while aboard space shuttle Discovery, according to NASA.
She spent 608 days in space throughout her career, placing her second on the list of most cumulative time spent in space by a NASA astronaut, per the agency.
Williams currently holds the record for most spacewalk time by a woman at 62 hours and 6 minutes across nine spacewalks, and was the first person to run a marathon in space, NASA said.
In June 2024, Williams and Wilmore were launched into space aboard the Starliner spacecraft as part of a test mission. They then spent the next nine months in space due to mechanical problems with their spacecraft.
Williams and Wilmore returned to Earth in March 2025. Wilmore retired from NASA four months later in August.
Speaking with PEOPLE in September 2025, Williams hinted that she was also considering retirement. "I think I might turn to the next chapter of life," she said at the time.
NASA Administrator Jared Isaacman described Williams in a statement as "a trailblazer in human spaceflight" whose "extraordinary achievements will continue to inspire generations to dream big and push the boundaries of what's possible."
"Congratulations on your well-deserved retirement, and thank you for your service to NASA and our nation," Isaacman stated.
Vanessa Wyche, director of NASA's Johnson Space Center in Houston, applauded Williams for being "a pioneering leader" while Scott Tingle, chief of the Astronaut Office, called her "incredibly sharp, and an all-around great friend and colleague."
"She's inspired so many people, including myself and other astronauts in the corps," Tingle said. "We're all going to miss her greatly and wish her nothing but the best."