Judith Hann (born 8 September 1942) is a broadcaster and writer specialising in science, food and the environment.

Hann's father was the former Derby County footballer and trainer Ralph Hann.

Hann attended the University of Durham, where she edited Palatinate, the university newspaper, for two terms in 1963.

Hann presented Tomorrow's World on BBC Television between 1974 and 1994, making her the programme's longest-serving presenter. She has since made television guest appearances, and also some TV commercials. In 1997, she appeared in a Shredded Wheat advertisement, in which she used her scientific judgement to inform viewers that the product could possibly help keep their hearts healthy. In 2006, she presented Two's A Crowd, a series on BBC Radio 4 that searched for the secrets of human identity. She runs her own media training and presentation skills company.

Hann lives on a farm near the small town of Lechlade, Gloucestershire, in the Cotswolds. She has written a book and taught courses about herbs, and grows many varieties of them in her garden.

Hann was married to John Exelby, a former executive at BBC News, who died in November 2019; they had two sons.