Barcoding a Lionfish’s Last Meal is a project that engages students in authentic research and uses molecular techniques to study an environmental issue—invasion of the lionfish. Red lionfish (Pterois volitans) are a voracious invasive species indigenous to Indo-Pacific waters that have the potential to greatly disrupt coral reef ecosystems. We report the initial data gathered from high school and university students as well as high school teachers attending professional development workshops. Data is shared on the iNaturalist website (see Resources) to allow widespread access for analysis. This project is now in its third year.