Tilly has raced internationally for Great Britain in a mix of U23 and Senior races, as well as domestically in the British Triathlon Super Series and British Elite Championships.
She has been named on the World Class Programme for the first time in 2024. 2023 saw her record a series of top-ten results across Europe Triathlon and World Triathlon events, ending the year with a silver medal in the senior race at Europe Triathlon Cup Alanya.
Tilly is based in Cardiff at the National Triathlon Performance Centre Wales but is originally from Norfolk. She’s been swimming competitively since she was nine and first took to triathlon in 2018 as a 17 year old when she found an enjoyment for running as well as swimming.
In 2021, Tilly finished third at the British Sprint Triathlon Championships before making her international debut at 2021 Europe Triathlon Cup Quarteira. The following year saw Tilly race regularly on the British Triathlon Super Series, ending the year third in the Senior Female Series. She ended 2022 with a bronze medal at 2022 Africa Triathlon Cup Dakhla, her first international medal.
Throughout the 2023 season, Tilly was part of the mixed relay team that finished sixth in the U23-Junior race at the Relay Championships in Hamburg and gold-medal winning team at the Europe Triathlon Championships in Balikesir. She finished fifth in the U23 Championships in Balikesir, crossing the line nineth overall. Later in the year, she represented Great Britain in her first World Championships. Racing in the U23 Championships, Tilly secured a sixth-place finish in Pontevedra.
As well as representing Great Britain, Tilly has gained experience from competing in the French Grand Prix and Super League Triathlon.