The Short Version
This claim is false on two counts. Jessie Buckley is Irish, not British — she was born in Kerry, Ireland, and every major outlet covering her 2026 Best Actress win identifies her as Irish. Her victory is historic as the first Irish Best Actress Oscar. Additionally, numerous British actresses have already won this award, including Vivien Leigh (1939), Julie Andrews (1964), Glenda Jackson (1969, 1973), Kate Winslet (2008), and Olivia Colman (2019).