Organizers
- Club SciKidz Houston
- Club Scikidz North Seattle
- Club Scikidz Queens NY
- Club Scikidz Riverside
- Club Scikidz South Charlotte
- Club Scikidz Treasure Coast
- Club SciKidz West Chicago
- Clyde Park District
- Coach Woottens Basketball Camp
- Cocolalla Lake Bible Camp
- Coconino County Parks and Recreation
- Code-it Hacks Inc.
- Coe Baseball LLC
- Coerver Premier - North Carolina
- Coerver United - United Soccer Coaching
- College of Marin Community Education
- College Scouting Bureau
- Colleyville Parks and Recreation Department
- COLLIER COUNTY
- Colorado Lacrosse
- Colorado Soccer School
- Colton Community Services
- Columbus Recreation and Parks Department
- Commerce City Recreation Department
- Commerce Parks and Recreation
- Common Ground
- Commonwealth Academy
- Communities in Schools of North Texas
- Community Boating Center, Inc.
- Community Education & Recreation
- Community Education Bowling Green Warren County
- Community House
- Community of Christ
- Community Sports League
- Concordia Preparatory School
- Concordia University Ann Arbor
- Connect Ministries
- Connecticut College
- Conroe, City of
- Cooper River Bridge Run
- Cooper Spur Alpine Team
- Coquitlam Sharks Aquatic Club
- Coral Reef Swim Race
- Coralville Parks & Recreation Department
- Cordova Recreation and Park District
- Core Athletics LLC
- Corporate Employees Recreation Association
- Corporation of the Town of Kirkland Lake
- Corpus Christi Parish
- Cottage Grove Recreation Department.
