Purpose: The happy-productive worker hypothesis posits that employee well-being is an important factor in work performance. Educational institutions around the world are facing both internal and external pressures to integrate sustainability into their practices, with the goal of protecting the planet and ultimately boosting profits. This paper explores the potential wider benefits of sustainability, including its relationship with employee well-being and performance, by investigating the influence of organisational sustainability on the happy-productive worker hypothesis. Design/methodology/approach: Educational institution employees from the UAE and USA (n = 199; 66.3% teachers) completed an online questionnaire measuring their well-being, perceptions of their organisations' environmental sustainability and three self-reported job performance measures (task performance, contextual performance and counter-productive workplace behaviours). Regression and mediation analyses were conducted to test hypothesised relationships. Findings: Both well-being and sustainability were positively associated with work performance. Furthermore, sustainability accounted for additional variance in performance beyond that accounted for by well-being. Sustainability partially mediated the relationship between well-being and performance, providing evidence of the importance of sustainability in the workplace. Originality/value: This study contributes to an emerging field by investigating the relationship between an organisation's sustainability and benefits of this for employees in terms of well-being as well as work performance. The findings provide further support for the happy-productive worker hypothesis and also the first evidence that educational institutions' sustainability can mediate this relationship.