Organizers
- Maximum Velocity Swimming
- Mayfield Marlins Swimming Club
- Mayflower Arts Center
- MC Elite
- MC High Performance Training
- McGaw YMCA
- McHenry County Conservation District
- McLean Community Center
- McLennan Dance
- MCN Sports Management
- McTavish Academy Of Art
- Mead Botanical Garden
- Mechanicsburg Area Recreation
- Mecklenburg County Park and Recreation
- Medical Training of the Palm Beaches
- Medina Fastpitch
- Medomak Sheepscot Regional Adult & Community Education
- MedWAR
- Melissa Kutcher Gymnastics Camp LLC
- Memphis Zoo
- Mendocino Coast Recreation and Park District
- Menomonie Parks and Recreation Department
- Mercer County Golf Academy
- Mercer Soccer Academy
- Merrohawke Nature School
- Methodist University Athletics - Baseball
- Methodist University Athletics - Men's Soccer
- Methodist University Athletics - Softball
- Metro Edge Figure Skating Club
- Metropolitan Performing Arts
- Mexican Heritage Plaza
- Mexico YMCA Mid-Mo Marlins Swim Team
- MHC Gulls
- Miami Gardens Parks and Recreation
- Miami Kids Triathlon
- Miami Stage Company
- Miami Swimming
- Michiana Day Camp
- Mid Hudson Heatwaves
- Mid-Coast School of Technology Adult Education
- Mid-Maine Regional Adult Community Education
- MidSouth Music Institute, Inc.
- Midwest Tournament Factory
- Mighty Movement
- Milan Parks and Recreation
- Mill Creek Recreation
- Millbrook Baseball and Softball League
- Millcreek Swim Team (MIST)
- Millennium Running
- Milngavie and Bearsden Amateur Swimming Club
