They include the Hawke's Bay Show which celebrated 150 years in 2013, and which this year will be held on October 19-21, as usual incorporating the Hawke's Bay Anniversary public holiday, while the showgrounds are also home to the New Zealand Horse of the Year Show each March.
Hastings mayor Sandra Hazlehurst said the outcome was "truly fantastic for our community".
"Council will immediately start the process to have the showgrounds vested as a reserve, which will protect it forever for the community," she said. "We are very much looking forward to completing that process and then preparing a Reserve Management Plan with the community."
The plan will set out how we look after the Tomoana Showgrounds and create opportunities for more events and improve facilities."
As part of the agreement, the showgrounds will be designated as a reserve managed by a trust with representatives of the A and P society, the council, and nearby Waipatu Marae, and the society will have 10-days free-use of the showgrounds each year, primarily around the show each October, and free use of office space.
With the show and the formation of the society dating back to an 1863 event near Havelock North, the showgrounds have been owned by the A and P society since 1911, although it was not until 1925 that the Hawke's Bay A and P Show was first held there.
It's always been one of the major shows in New Zealand, being acclaimed as the Royal Agricultural Society's Royal Show in-turn with the Manawatu, Southland, Waikato and Canterbury shows each year for many years.
Amid a new era of Royal Show allocation, the showgrounds became at least a semi-permanent home of the Royal Show in 2015, with contracts to stage the Royal event annually through to 2021.
The sequence was broken by the Covid-19 pandemic, leading to a scaled-down show in 2020, cancellation last year and a rethink by the RAS as to the future of the Royal Show.
The RAS website lists 85 A and P associations, most more than a century old and all likely to stage shows from single day to three or four day events from September this year to April-May 2023, most recovering from cancellation last season.
The show is one of five annually in the wider Hawke's Bay area from .Wairoa to Dannevirke.