Big Brothers Big Sisters of Miami is the premier mentoring organization of South Florida. Every day, we awaken possibilities for thousands of Miami’s kids – one child and afternoon at a time – through professionally supported, one-on-one relationships with caring adult volunteers. BBBS Miami has over 55 years of history and experience in the community, since our founding in 1958. We rank in the top 30 largest BBBS agencies in the country and #1 in Florida. BBBS Miami.