The successes included Hotham Park in Bognor Regis, Mewsbrook Park in Littlehampton, Grenfell Park in Maidenhead and Vulcan Park in Workington.
Head of leisure services at Royal Borough of Windsor & Maidenhead Kevin Mist said "This year has been challenging but we were delighted to have retained our six Green Flags in addition to a new flag for Grenfell Park."
Arun District Council parks manager Oliver Handson added: "Our three Green Flag parks have again met the required standard. This was no small achievement given the challenges this year."
ISS managing director Phil Jones said "Our Green Flag wins show how strong partnership working breeds success. We will continue to seek opportunities to improve our service delivery and to explore with clients further joint working."