Barber made her international debut at the
2014 Commonwealth Games, finishing third with 62.95 m. She competed at the
2015 World Championships in Beijing without qualifying for the final. A back injury in early 2016 disrupted her preparation for the
2016 Summer Olympics and she finished 28th in qualifying. Barber had a breakthrough season in 2017. She produced three consecutive personal bests in competitions in Turku, Lausanne and London. At the
World Championships, she qualified automatically for the final and finished 10th. She finished the season with a silver medal at the Diamond League Final in Zurich and another personal best of 64.53 m. Barber won gold at the
2019 Oceania Athletics Championships with a personal best and championship record 65.61 m throw. At the
Spitzen Leichtathletik Luzern in July, she won gold and improved on her personal best, throwing 67.70 m. This also moved Barber to second on the
Oceanian list behind Mitchell, and into 12th in the
overall list. She won the
gold medal at the
2019 World Championships with 66.56 m on the final throw, moving her from 4th to 1st place. She was recognised in the
Canberra Sport Awards as Female Athlete of the Year. In 2021, following the
COVID-19 disruptions to competition, Barber threw 61.09 m to place second at the national titles. Barber won bronze in the final at the
2020 Summer Olympics in
Tokyo, throwing 64.56m. At the
2022 World Athletics Championships, Barber won a gold medal in javelin, making her the first woman to ever retain the women's World Championships javelin title. Later that year, she also won a gold medal at the 2022 Commonwealth Games with a throw of 64.43m. ==Competition record==