A Regius Professor is a university professor who has, or originally had, royal patronage or appointment. They are a unique feature of academia in the United Kingdom and Ireland. The first Regius Professorship was in the field of medicine, and founded by the Scottish King James IV at the University of Aberdeen in 1497. Regius chairs have since been instituted in various universities, in disciplines judged to be fundamental and for which there is a continuing and significant need. Each was established by an English, Scottish, or British monarch, and following proper advertisement and interview through the offices of the university and the national government, the current monarch still appoints the professor. This royal imprimatur, and the relative rarity of these professorships, means a Regius chair is prestigious and highly sought-after.

The University of Aberdeen is a public research university in Aberdeen, Scotland. It was founded in 1495 when William Elphinstone, Bishop of Aberdeen and Chancellor of Scotland, petitioned Pope Alexander VI on behalf of James IV, King of Scots to establish King's College, making it one of Scotland's four ancient universities and the fifth-oldest university in the English-speaking world. Along with the universities of St Andrews, Glasgow, and Edinburgh, the university was part of the Scottish Enlightenment during the 18th century.