Organizers
- Corning High School Sports Association - Boosters Club
- Cornshucker Baseball
- Cornshucker Baseball Club
- Cornwall Lions Club
- Corona del Mar Chamber of Commerce
- Corona Eagles FC
- Corona Girls Softball Association
- Corona National Little League
- Coronado Islanders
- Coronado Little League
- Coronado Surf Club
- Coronado Tennis Center in Hot Springs Village
- Coronado Youth Softball
- Corporal Christopher M. Shea Memorial Scholarship Fund
- Corporate Employees Recreation Association
- Corporation of the Town of Kirkland Lake
- Corpus Christi Aquatic Alliance Club Estates Marlins
- Corpus Christi Athletic Club
- Corpus Christi Catholic Church
- Corpus Christi Country Club
- Corpus Christi Parish
- Corpus Christi Roadrunners
- Corpus Christi Sparking City Fast Pitch League
- Corpus Christi Tennis Association
- Corral Z
- Corrigan Sports Enterprises
- Corso Beach Volleyball
- Cortland Bible Camp
- Cortland Bible Club Camp
- Cortland Community Gymnastics
- Cortland County Family YMCA
- Cortlandt National Little League
- Cortlandt Softball Little League
- Corvallis Environmental Center
- Cory Lidle Foundation
- Cosumnes River College Sports Camps
- Coto de Caza Golf Club
- Cotswold Running LTD
- Cottage Grove Recreation Department.
- Cottonwood Golf Course-John Klein, PGA
- Cottonwood Hills Golf Course
- Cottonwood School
- Cougar Aquatic Team -NJ
- Cougar Soccer Academy
- Cougar Soccer Camp
- Coughlin Chevrolet of Pataskala
- Coulee Region Tennis Association
- Council Bluffs Soccer Club
- Council Rock
- Council Rock Basketball
