The Society was constituted in 1858 as the Isle of Man Agricultural Society and in 1951, His Majesty King George VI approved of the Society being called the Royal Manx Agricultural Society. Historically there were two annual shows. The Spring Show at the Nunnery and the Northern Show held on Lezayre Playing Fields. In 1961 the Douglas show moved to King George V Park and in 1974 the first northern show was held at Staward Farm, Sulby. The Show continued to alternate between Douglas and Ramsey until 1990 when King George V Park and the adjoining Bowl were needed for the new National Sports Centre, until 2010 all the Shows continued to be held at Sulby. In 2011 the Show moved to Knockaloe in Patrick where the Show is now held every year.

Each year the Royal Show is put together by volunteers in the three weeks preceding the Show, and dismantled the following week. This work is extremely weather dependent, both in terms of raising marquees etc, and also in the amount of the time that our volunteers can spare from summer work on their own farms.

The Royal Manx Agricultural Society is a self-funding Manx registered charity. It has seven Directors, and a Council of 60 members representing all areas of the island who are elected for a period of two years. In addition, Past Presidents of the Society attend meetings and have voting rights.