Purpose: This paper aims to describe the development, promotion and evaluation of sustainability learning experience database (SLED), a university-curated database of sustainability experiences to augment formal student learning. Its purpose was to encourage students to participate in experiential learning, to facilitate students' critical appraisal of programs ostensibly designed to create sustainability and to, thus, develop students' sustainability self-efficacy and employability. Design/methodology/approach: In total, 55 sustainability experiences were curated and placed into the SLED database, which was promoted to students in nine subjects. Supporting materials designed to assist critical evaluation, reflection on experiences and to build student employability were also developed. A comprehensive mixed-methods evaluation of the program was conducted. Findings: The quantitative evaluation revealed some changes in environmental behaviors, depth of critical sustainability thinking and graduate attributes. The qualitative evaluation revealed that students see the value of a university-curated database of experiences and provided ideas for improvements to the database. It also revealed examples of higher-order learning facilitated by SLED. Research limitations/implications: Recruitment and attrition of research subjects, common challenges in pedagogical research, were experienced. "Opt-out" is one response to this but it comes with ethical challenges. Originality/value: This exploratory study demonstrates the potential of SLED to build students' sustainability efficacy and suggests ways in which it and similar programs can be developed for improved student and sustainability outcomes. Namely, the use of an online platform closely associated with existing learning management systems, higher-level institutional stewardship, closer curriculum integration and close partnering with credentialing programs.