Fields in Trust, which was formerly known as the National Playing Fields Association, was set up by King George V in 1925.
The aim was to ensure all people young or old, able or disabled, should have access to free, local, outdoor space for sport, play or recreation.
The group's flagship policy is called Fields in Trust which sets out to protect as many outdoor recreation spaces as possible as a celebration of the Queen's Diamond Jubilee, the London Olympics and the Commonwealth Games.
Fields in Trust works with the owners of green spaces to protect them in the long term through a legal agreement.
At present there are only two such agreements in Glasgow - King George V park in Carnwadric and King George V pitch in Carmunnock.
As part of the Jubilee celebrations, Fields in Trust launched a scheme to designate a number of Queen Elizabeth 11 fields across the UK.
City council officers nominated 28 sites which they suggested should be covered by the legal agreement.
These cover large areas like the Botanic Gardens, Cathkin Braes and Glasgow Green.
But there are also smaller areas of green including Naseby Park, Garnethill Peoples Park and Binghams Pond.
The agreement means the sites shall only be used as public playing fields, open spaces, parks or for any other public recreation, leisure or sporting use.
If the council wants to change the use of a site, sell or build on it, it has to get the permission of the Fields in Trust organisation.
If it wants to remove a site from the scheme an alternative site must be added as a substitute.
Alistair Watson, the city council's sustainability and the environment spokesman, said: "By nominating a number of parks, the council is showing its commitment to promoting active lifestyles through the protection of our green space.
"This is yet another opportunity to build on the magnificent legacy of the Glasgow 2014 Commonwealth Games across the city.
"The signing of this agreement is great news for Glaswegians as it states that these parks will only be used for public recreation. Essentially, this is a real badge of honour for these parks."