Godfrey Harold Hardy (February 7, 1877 - December 1, 1947) was a prominent British mathematician, famous for his achievements in number theory, especially his work on prime numbers. Non-mathematicians know him largely for two things: His autobiography, A Mathematician's Apology, (ISBN 0521427061), which was published in 1941 and may be the layman's best insight into the mind of a working mathematician; and his mentorship of the Indian mathematician Ramanujan, a relationship that echoed the conflict and cooperation between East and West which have marked modern history.

Hardy was Sadleirian Professor at Cambridge from 1931 to 1942. He is also known for formulating the Hardy-Weinberg principle, a basic principle of population genetics, independently from Wilhelm Weinberg in 1908. From 1911 he collaborated with Littlewood, and from 1914 with Ramanujan.

Hardy never married, in his final years he was cared for by his sister.