Friends of Cherry Lawn Park
- Volunteer group of residents dedicated to preserving the public park.
- http://foclp.darien.org/

Darien Environmental Group
- Nonprofit volunteer organization established to educate residents about ways in which they can change consumer and lifestyle habits to benefit the environment.
- http://www.darienenvironmentalgroup.org/

Darien Audubon Society
- Organization overview, newsletter and information on field trips, special events, speaking programs, projects and birding areas.
- http://audubon.darien.org/

Darien Land Trust
- Land conservation agency which acquires and maintains areas of the town to be held as open space for the benefit of the community.
- http://dlt.darien.org/