Exotic species introduced through the pet trade pose an ecological and economic threat to the Great Lakes region. Trachemys scripta elegans, the red-eared slider turtle, is a globally invasive species already present in the Great Lakes basin whose distribution and potential for spread is poorly known. We assembled a detailed dataset on T. s. elegans occurrence and establishment in the region and created a niche model to assess the potential for the spread of this species under current climate conditions and future scenarios. We found T. s. elegans occurs throughout the Great Lakes basin and suitable area will likely increase from 26% to 39–50% of the entire basin by 2050, with Lake Erie at greatest risk with ∼95% of its total area suitable for T. s. elegans by 2050. These findings highlight the need for further research to assess impacts of T. s. elegans on native species and proactive efforts to prevent its further spread.