The potential of Catherine O'Donnell was spotted at the age of 18 when she represented England U20 while playing for Firwood Waterloo. Her first experience of the Six Nations came in February 2018 when she was a second-row replacement for the Red Roses against Scotland and Ireland. She scored her first international try in England’s 37-15 win over Ireland at Twickenham in the 2018 Quilter Internationals. After being awarded a full-time England contract in 2019, Catherine started in four of England’s five Women’s Six Nations games as they won the Grand Slam. A reliable figure in Simon Middleton’s ranks, she started all but one of England’s Super Series fixtures in San Diego. Cath was part of England’s title winning Six Nations campaign in 2021 but missed the autumn internationals and 2022 Six Nations campaign through injury before featuring in the squad for the delayed 2021 Rugby World Cup. She featured in the squad for the 2023 TikTok Women’s Six Nations before being named in the Red Roses' squad for the inaugural WXV tournament in New Zealand. Most recently, Catherine was named in John Mitchell’s squad for the 2023 Guinness Women’s Six Nations.