Thomas Kirkwood (born 1951, Durban, Southern Africa) is an English biologist who made his contribution to the biology of ageing by proposing the concept of Disposable soma. He is currently a researcher in Newcastle university and heads The Institute for Ageing and Health in its School of Clinical Medical Sciences. He is the author of "Time of Our Lives: The Science of Human Aging" (1999) and "The End of Age: Why Everything About Aging Is Changing" (2001), co-author of "Chance, Development, and Aging" (2000, together with Caleb E. Finch).