Sir Ian David Diamond DL FRSE FBA FAcSS FLSW (born 14 March 1954) is a British statistician, academic, and administrator, who served as Principal and Vice-Chancellor of the University of Aberdeen until 2018.

Diamond's previous appointments include Chief Executive of the Economic and Social Research Council, Chair of the Research Councils UK Executive Group, and Deputy Vice-Chancellor at the University of Southampton.

[4] Chair of Lloyds Banking Group Foundation for England and Wales, Visiting Fellow at Nuffield College, Oxford.

In 2016 he led a review of University finance in Wales which was commissioned by the Welsh Government, which recommended that grants towards tuition fees should be replaced with support for living costs instead.

[9] Diamond's appointment as National Statistician, in succession to John Pullinger, was announced on 6 August 2019, and he took office on 22 October 2019.