Indo-Pacific lionfish (Pterois volitans and P. miles) have established populations throughout the tropical Western Atlantic Ocean with demonstrable effects on native species, fisheries, biodiversity, and ecosystem processes. Effective management of this invasion is proving to be beyond the capacity of natural resource management agencies alone and requires innovative approaches as well as collaboration among a diverse set of stakeholders. In response, government entities and other groups throughout the W. Atlantic region have mobilized citizen groups, particularly SCUBA divers, to physically remove lionfish and to collect important data needed to manage the invasion. Here, we survey lionfish citizen science initiatives to inventory these programs in terms of member composition, cooperation with local governments, financial support mechanisms, operations, objectives, scientific involvement, and successes and shortcomings. We categorize these operations based on their development, structure, and effectiveness since initial detection of lionfish in the mid-1980s, and consider how lessons from lionfish programs in the W. Atlantic can inform groups working on the novel invasion in the Mediterranean. Patterns from the broad emergence of lionfish citizen science initiatives and groups can increase public engagement-in and scientific impact-from other environmental citizen science programs.