The Royal Highland and Agricultural Society of Scotland (RHASS) was founded in 1784 as The Highland Society of Edinburgh.

It was formed out of concern at the suffering endured in agricultural districts by a great failure of crops in 1782. The institution looked to improve transport conditions in the Highlands and Islands, to advance agriculture and introduce useful trades and manufactures. Its sphere of influence and support expanded to cover the whole of Scotland, and the Society awarded medals for essays on subjects in agriculture, prizes for improvements to farms, and premiums awarded for livestock, woollen products and crafts.

The Society engaged the services of William Dick to lecture on Veterinary Science (the beginnings of the Dick Vet School) and also commissioned the compilation of the first Gaelic dictionary which was published in 1825. Papers recounting these activities are held within the library and archive which also contains materials pertaining to the history of the Society and its activities, as well as the history of Scottish agriculture. RHASS is responsible for organising the annual Royal Highland Show.

The Society was granted its Royal status by King George VI in 1948.