RBO or Rbo may refer to: Rock et Belles Oreilles, a Québécois radio, television and stage comedy group MTA Regional Bus Operations, the surface transit division of New York's Metropolitan Transportation Authority Ragnarok Battle Offline, a computer game Reliability-based optimization, a multidisciplinary design optimization method Rubidium oxide, the chemical compound Rb2O Robert Brownlee Observatory in Lake Arrowhead, California Rule-Based Optimization, an SQL Query plan optimization technique Red Buttes Observatory near Laramie, Wyoming Rang Badalti Odhani Royal Ballet and Opera, British performing companies based at the Royal Opera House, London Rank-biased overlap, used in ranking information