Find 98 gated apartments in O'Fallon, MO on ForRent.com. Gated apartments offer an added layer of security and privacy to renters' lifestyles. Renters most often enter the community via key fob, password-protected keypad, or 24-hour security, meaning that only authorized residents and guests have access. Start your search today and enjoy added security and peace of mind with O'Fallon, MO gated apartments.