They released a picture showing the grounds of the Boughton Estate near Kettering (pictured above, left) looking virtually untouched, with the exception of grass stains made by tents.
In a post published on Twitter, they wrote: "Greenbelters. You're an amazing bunch. You left the site as you found it. Thank you."
The view contrasted aerial pictures taken after Reading Festival (pictured above, right) earlier this month which showed thousands of abandoned tents and countless pieces of litter.
Greenbelters. You're an amazing bunch. You left the site as you found it. Thank you. Here's how you did it: #gb17 #thecommongood pic.twitter.com/djz2mwncoX
— Greenbelt Festival (@greenbelt) August 30, 2017
The BBC reported on Wednesday that volunteers from a community group have been collecting leftover items to take to homeless people.
The three-day festival in Berkshire attracted 90,000 revellers this year, significantly more than the crowds who attended Greenbelt.
The rubbish at Reading Festival came despite pleas from organisers that guests help keep the event "clean and green". Recycling points and returnable deposits for returning cups and bottles were also used.
Founded in 1974 and "energised by a progressive Christian worldview", Greenbelt celebrates arts, faith and justice. This year's event wrapped up earlier this week and boasted a line up which included priest and television personality Rev Kate Bottley and Newton Faulkner.