Daphne J. Osborne (7 March 1930 – 16 June 2006) was a British botanist. Her research in the field of plant physiology spanned five decades and resulted in over two hundred papers, twenty of which were published in Nature. Her obituary in The Times described her scientific achievements as "legendary"; that from the Botanical Society of America attributed her success to "her wonderful intellectual style, combined with her proclivity for remarkable and perceptive experimental findings".