Organizers
- Sidney Regional Medical Center
- Siembida & Boggs Philanthropic Foundation
- Siena College Academic Camps
- Siena College Athletic Camps
- Siena College Athletics
- Siena Golf Academy
- SIENA WORKSHOP
- Sienna Plantation Golf Club
- Sienna Ranch
- Sierra Adventure Sports
- Sierra Cascades Multisport
- Sierra Club
- Sierra Club Canada Foundation
- Sierra La Verne Country Club
- Sierra Music and Arts Institute
- Sierra Nevada Community Sailing
- Sierra Pacific Mission Center
- Sierra Vista Sunrise Rotary Club
- Siggi Nagele Inc.
- Sigma Nu
- Signature Club Gators
- Signature Golf Academy at Rolling Hills GC
- Sigsbee Charter School
- Silence of Mary Home
- Silicon STEM Academy
- Silicon Valley Leadership Group Foundation
- Silkworth Golf Academy
- Silsbee FCCLA
- Silver Back
- Silver Circle Sports Events, LLC
- Silver Comet Races
- SILVER CREEK ACADEMY
- Silver Lake Duathlon
- Silver Lake Wesleyan Camp
- Silver Lining Circus Camp
- Silver Maple Camp, Inc.
- Silver Run Ski Foundation
- Silver Salmon Racing
- Silver Spring Township
- SILVERBACK
- Silverback Fitness LLC
- Silverdale Baptist Academy
- Silverlake Conservatory of Music
- Simi Valley Baseball League
- Similkameen Swim Club
- Simmons Bank Goodlettsville 5k
- Simmons Center
- Simon Clough
- Simpson County Literacy Center
- Simsbury Badminton Club