Rachael Blackmore, the first female jockey to win the Grand National, announced her retirement from horse racing with immediate effect on Monday.
Blackmore, 35, confirmed the decision on social media saying her "days of being a jockey have come to an end."
In 2021, Blackmore made history by becoming the first female to win the Grand National in the race's 182-year history.
She rode the Henry de Bromhead-trained Minella Times to the trailblazing victory at Aintree which came 44 years after Charlotte Brew became the first woman to ride in the world's most famous steeplechase.
The Irishwoman was also the first female jockey to win the Champion Hurdle, doing so aboard Honeysuckle, the same year as her Grand National triumph.
She then clinched another historic first when she guided A Plus Tard to the Cheltenham Gold Cup in 2022.
"I feel the time is right," Blackmore said in a post on social media.
"I'm sad but also incredibly grateful for what my life has been for the past 16 years. I just feel so lucky, to have been legged up on the horses I have, and to have experienced success I never event dreamt could be possible."
Blackmore won 575 of her 4,566 career races. Her last victory came aboard Ma Belle Etoile in Cork on Saturday.