Katharine Sara Walker (born 30 October 1994 in Belfast) is a Northern Irish nurse, radio presenter and beauty pageant titleholder who was appointed as Miss Universe Ireland 2021 and represented Ireland at the Miss Universe 2021 pageant in Eilat, Israel. She was previously crowned as Miss Northern Ireland in 2018.^[1]

Walker was born and raised in Belfast, Northern Ireland. She is the younger sister of Gareth Walker with her parents Fred Walker and Wendy Walker. Walker went to Queen’s University Belfast in Belfast where she earned her bachelor’s degree in children’s nursing. In 2016, she started working as a pediatric nurse in intensive care at the Royal Belfast Hospital for Sick Children in Belfast. In 2019, she started working for Cool FM as a radio presenter.

On May 28, 2018, Walker competed at the Miss Northern Ireland 2018 pageant, where she won the title. On December 8, 2018, Walker represented Northern Ireland at Miss World 2018 and competed against 117 other candidates at the Sanya City Arena in Sanya, China, where she finished in the Top 30. She also won the Top 24 at Miss World Sport award at the contest.^[2][3]

On December 21, 2020, Walker was one of the 12 finalists who competed for the Miss Universe Ireland 2020 title in a virtual coronation ceremony, where she finished in the Top 7 and lost eventually winner Nadia Sayers. On November 8, 2021, Walker was appointed as Miss Universe Ireland 2021 and represented Ireland at Miss Universe 2021 in Eilat, Israel on December 12, 2021.^[4]