2016 World Short Course Championships (Windsor, Ontario, Canada)
Melverton won bronze in the 800 free (8:16.51), finishing behind Americans Leah Smith (8:10.17) and Ashley Twichell (8:11.95). She also placed 13th in the 400 free (4:06.51).
2018 Commonwealth Games (Gold Coast, Australia)
Melverton earned a bronze medal in the 800 free (8:28.59), finishing third behind countrywomen Ariarne Titmus (8:20.02) and Jessica Ashwood (8:27.60).
2019 World Championships (Gwangju, Korea)
Melverton won gold as part of Australia’s 4×200 free relay team. Melverton swam the anchor leg for the Aussies in the preliminary heats, clocking a 1:59.18, following Leah Neale (1:58.30), Madison Wilson (1:56.46) and Brianna Throssell (1:56.70). Australia went on to win the gold, clocking a world record 7:41.50 in the final with a lineup of Ariarne Titmus, Madison Wilson, Throssell and Emma McKeon.
Individually, Melverton finished seventh in the 800 free (8:25.07) and 1500 free (16:01.38) and 11th in the 400 free (4:09.56).
2022 World Championships
Melverton started her meet on day 1 in the 400 free, qualifying for the final and ultimately finishing 7th in 4:05.62. On day 5, Melverton helped Australia to a silver medal in the 800 free relay, splitting 1:55.91 on the 3rd leg. On day 7, Melverton won individual silver, placing 2nd in the 800 free (8:18.77) behind Katie Ledecky.
2023 World Aquatics Championships (Fukuoka, Japan)
Melverton swam the 800 free relay where she split 1:57.64 on the prelims anchor. The finals squad took gold and set the world record. Melverton also took on the 400 IM where she finished 13th in 4:41.87, off her 4:39.65 from trials that would have just missed the final.