[2] Ellis won the 2016 Australian Open boys' doubles alongside Alex de Minaur.

Between 2015 and 2017, he competed in the ITF Men's Circuit around Australia, Asia and Europe, with his best result being a semi-final appearance in August 2017 in the Thailand F6 Futures tournament in Nonthaburi.

[3] At the 2018 Shimadzu All Japan Indoor Tennis Championships, Ellis had his best Challenger-level performance to date, winning his qualifying matches then defeating two previous tournament champions in fifth seed Tatsuma Ito and third seed Go Soeda en route to a semi-final loss against fellow Australian and eventual champion John Millman.

After a great season in 2024, Ellis was awarded a wildcard to compete in the 2025 Australian Open qualifying competition, aiming to reach a grand slam for the first time.

Despite losing the opportunity to compete for a singles grand slam he did play with his partner Thomas Fancutt in the Australian Open.