In recent years, the airport industry is facing the effects of the growing pressure towards sustainability. In fact, airports have often been accused of having strong environmental and social impacts. This circumstance shed light on the need for airports to provide stakeholders with precise information about the social and environmental effects of their activities. The importance of sustainability disclosure in the airport industry is also attracting the interest of academics. However, studies are still limited and there is a lack of contributions aimed at identifying the drivers of sustainability disclosure in the airport industry. This work aims to fill this gap by analyzing, under the lens of legitimacy theory, the impact of business size, business complexity and corporate visibility on the level of sustainability information disseminated by airports. To this end, a manual content analysis is performed on a sample composed by 145 large European airports to measure the level of sustainability information disseminated. Furthermore, a multiple regression analysis is performed to examine the role played by business size, business complexity and corporate visibility on the level of sustainability disclosure. The results show that the number of passengers, the cargo quantity, the number of terminals and gates and the level of social media exposure represent positive drivers of the sustainability disclosure of the European airports. This study contributes to enriching the academic literature in several ways and offers important managerial implications.