Iolo Tudur Williams (/ˈjɒloʊ/; Welsh pronunciation: ['jɔlɔ]; born 22 August 1962) is a Welsh ornithologist, nature observer, television presenter and author, best known for his BBC and S4C nature programmes, working in both English and his first language of Welsh. After a 14-year career with the RSPB, in 1999 Williams became a full-time TV presenter. He has written a number of books about the natural world.