As water scarcity increases, we must turn to underutilized sources such as treated wastewater. While work has been done on barriers to public acceptance, less work has been undertaken to explore motivations that may incentivize adoption of this potential water source. Using data collected from respondents in four global sites (in Guatemala, Fiji, New Zealand, and Spain), we (1) analyzed how four motivators (cost, current and future water shortages, and ecological conservation) influenced respondents' willingness to use treated wastewater and (2) examined if respondents' willingness varied across contexts based on the level of wastewater treatment available. Despite a focus in previous research on the role of reducing cost and providing economic incentives for wastewater reuse adoption, cost was broadly the least motivating factor while ecological conservation and future water shortages were the two strongest motivators across all sites. Additionally, respondents in sites with low levels of wastewater technology were more likely to express a willingness to use treated wastewater given any motivator.