This study aims to investigate metaphors of preservice teachers, who are the potential future educational leaders, regarding sustainability according to their knowledge level of sustainability. The study used the convergent design, a mixed-method study, where both quantitative and qualitative data are collected and analyzed. The participants consisted of 867 preservice teachers from different departments of a public university in Turkey. The data were collected using Knowledge Test and Metaphor Determination Form whose reliability and validity studies were also conducted. Cluster analysis was used to analyze the quantitative data and the preservice teachers were categorized according to their knowledge level of sustainability. Content analysis was used to analyze the qualitative data and using the results obtained the preservice teachers’ metaphors were categorized. The results revealed that the preservice teachers’ knowledge levels of sustainability are above the middle-level. The cluster analysis results showed that the preservice teachers are categorized into three groups: low, middle, and high. The preservice teachers created 32 meaningful metaphors under four different categories (vital, economic, social, and will-o-the-wisp). The results also showed that the metaphors created by the preservice teachers significantly vary by their knowledge level of sustainability.