Organizers
- Columbia University Cubs Camp
- Columbia University Little Lions Camp (formerly Cubs Camp)
- Columbia Valley Hockey School
- Columbia Wrestling Club
- Columbiettes
- Columbus Bike Racing Club
- Columbus Catholic Schools
- Columbus Christian Academy Camps
- Columbus Crew SC
- Columbus Idea Foundry
- Columbus Park
- Columbus Recreation
- Columbus Recreation and Parks Department
- Columbus Recreation and Parks Department/B.A.T.S.
- Columbus Regional Tennis Association (CORTA)
- Columbus Running Company
- Columbus Sharks Masters Swim Team
- Columbus Unschooler's Co-Op
- Comb. Co. #1 Ayer Fire Department
- Combat Air Museum
- Come Join the BAND!
- Comedy Sportz Theatre of Chicago
- ComedyCity
- Comer Baptist Church
- Commack Volunteer Ambulance Corp 5k Run/Walk
- Commander Run
- Commando Challenge
- Commando Outdoor Fitness Events
- Commerce City Parks and Recreation Department
- Commerce City Recreation Department
- Commerce Parks and Recreation
- Commodore Perry Lions Little League
- Common Ground
- Common Ground - CT
- common ground outdoor adventures
- Common Threads
- Common Threads Austin
- CommonGround Golf Course
- Commonwealth Academy
- Communities In Schools
- Communities In Schools of Mancelona
- Communities In Schools of Moore County
- Communities in Schools of North Texas
- Community Arts Experience (C.A.E.)
- Community Boat Building
- Community Boat Building/ Third Sector New England
- Community Boating Center, Inc.
- Community Caring Center of Boynton Beach, Inc.
- Community Caring Center of Greater Boynton Beach, Inc.
- Community Centre 55
