An Area of Outstanding Natural Beauty (AONB; Welsh: Ardal o Harddwch Naturiol Eithriadol, AHNE) is one of 46 areas of countryside in England, Wales, or Northern Ireland that has been designated for conservation due to its significant landscape value. Since 2023, the areas in England and Wales have also adopted the name National Landscape (Welsh: Tirwedd Cenedlaethol).
Areas are designated in recognition of their national importance by the relevant public body: Natural England, Natural Resources Wales, and the Northern Ireland Environment Agency respectively. On 22 November 2023, following a review, the AONBs in England and Wales adopted the National Landscapes name, and are in the process of rebranding. AONBs in Northern Ireland did not rename. The name "area of outstanding natural beauty" is still the designated legal term.