Effective fisheries management requires a detailed understanding of the life history strategies of managed species. The Queen Triggerfish Balistes vetula supports productive fisheries in the western Atlantic, including the U.S. Caribbean. We utilized a combination of fishery-dependent and fishery-independent samples to assess the size structure, sex ratio, size at maturity, spawning season, and spawning frequency for a Queen Triggerfish population in the U.S. Caribbean. From 2013 to 2018, 1,148 samples were collected, ranging in size from 67 to 434 mm FL. This study provides important life history information from an exploited population and is the first to describe Queen Triggerfish reproductive biology in detail for the Caribbean. We documented that the Queen Triggerfish is a sexually dimorphic species characterized by a medium size at maturity. The smallest sexually mature male and female were 184 and 215 mm FL, respectively. Lengths at 50% sexual maturity (L 50 ) for males sampled from Puerto Rico and St. Croix, U.S. Virgin Islands, were similar (206 and 211 mm FL, respectively) and were significantly smaller than the L 50 values for females (Puerto Rico: 256 mm FL; St. Croix: 245 mm FL). Queen Triggerfish, nesting benthic spawners, exhibited group-synchronous oogenesis and indeterminate fecundity over the spawning season that started as early as