Proud Kungarakan and Gurindji woman Allirra Jennings has become the first Indigenous woman to complete all six of the world's major marathons.

Ms Jennings completed the feat after crossing the finish line in the Boston Marathon earlier this month.

Suffering a head cold at the time, she completed the 127th running of the race alongside nearly 30,000 competitors in a time of 5:11:12.

"If you would've said to me 10 years ago that I would be running marathons, I would have laughed straight in your face," she told ABC.

Ms Jennings became the first Indigenous women to complete all six world marathons after first running in the New York City Marathon in 2014, following her selection as part of the Indigenous Marathon Project team.

She then went on to complete marathons in Berlin, Chicago, London and Tokyo as a self-funded solo athlete.

Finishing all six of the world's major marathons is a feat completed by just 278 Australians.

Allirra Jennings completed her sixth major marathon on just over five hours. (Image: Natasha Fyles Facebook - image cropped)

Ms Jennings' motivation to begin running marathons came about after her grandmother passed away from diabetes, a chronic disease that disproportionally affects Indigenous Australians.

Weighing 107kg at the time, the then 27-year-old realised she needed to make lifestyle changes to prevent further health issues.

"To watch my grandma fighting for her life, and I was just eating mine away," Ms Jennings said.

"It was a big kick in the guts ... I knew then and there that I was going to start honouring the body that I was given."

According to Aboriginal and Torres Strait Islander Health Framework figures, approximately 13 per cent of Indigenous people have diabetes with the disease causing 7 per cent of Indigenous deaths between 2015 and 2019.

Receiving a Six Star Finisher certificate and medal, Ms Jennings joins approximately 11,000 people who have completed the world's six major marathons.

After completing the Boston Marathon, she said she would like to see more Indigenous Australians consider long distance running.

"I do think we have the good genes for long-distance running," she said.

Ms Jennings' first marathon was the New York Marathon, which she completed as part of the Indigenous Marathon Foundation team in 2014. (Image: The Indigenous Marathon Foundation Facebook)

"We're natural athletes and, if we train our bodies the right way, we can achieve great things."

Ms Jennings is originally from Humpty Doo, near Darwin.

Following the completion of her sixth marathon, Northern Territory Chief Minister Natasha Fyles commended Ms Jennings' achievement.

"Allira - what an absolute champion you are," she said.

"Congratulations on your achievement and all the hard work and perseverance that's gotten you there.

"The Northern Territory couldn't be prouder to call you our own."

Ms Jennings is set to continue marathon running with her next event being a return to the Berlin Marathon in September.