Brianna Throssell OAM (born 10 February 1996) is an Australian professional swimmer currently representing DC Trident at the International Swimming League.
Throssell competed in the 2014 Summer Youth Olympics, where she won seven bronze medals. She represented her country at the 2016 Summer Olympics in Rio de Janeiro where she finished third in the semi-finals with a time of 2:07:19 behind Zhou Yilin and Zhang Yufei. She qualified for the final and finished last with a time of 2:07:87.
Throssell again represented Australia at the 2020 Summer Olympics, held in Tokyo in 2021, where she swam in the 100m and 200m butterfly events, coming in 8th place in the final of the 200m event. She won a gold medal in the Women's 4 x 100 metre medley relay and a bronze medal in the Mixed 4 x 100 metre medley relay after swimming the butterfly leg in the heats for both events. She also won a bronze medal in the Women's 4 x 200 metre freestyle relay after swimming in the heats of that event.
In the 2022 Australia Day Honours Throssell was awarded the Medal of the Order of Australia.