Harold Henry Joachim, FBA (/ˈdʒoʊəkɪm/; 28 May 1868 – 30 July 1938) was a British idealist philosopher.
A disciple of Francis Herbert Bradley, whose posthumous papers he edited, Joachim is now identified with the later days of the British idealist movement.
Harold Henry Joachim was born in London, the son of a wool merchant who had come to England as a young man from Hungary.
He was elected to a Prize Fellowship at Merton College in 1890, and in 1892 became a philosophy lecturer at the University of St Andrews.
He became Wykeham Professor of Logic of the University of Oxford from 1919, succeeding the realist John Cook Wilson, and occupied the chair until his death.