Alexandra Louise Mayer, born 2 June 1981, is a British Labour Party politician who has represented Dunstable and Leighton Buzzard as Member of Parliament since 2024. Before entering Westminster, she served as a Member of the European Parliament for the East of England region between 2016 and 2019, giving her significant experience in both domestic and European legislative contexts during a particularly notable period in British politics.

Mayer's political career has spanned two distinct parliamentary institutions, allowing her to develop expertise across a range of policy areas at both national and regional levels. Her transition from the European Parliament to the House of Commons reflects the changing political landscape in the United Kingdom. She now writes commentary for Comment Central.