Abstract Background Iodine is an essential trace element, which is important for human metabolism, growth and mental development. Iodine deficiency may still occur in Europe and the use of iodised salt is an effective measure to enhance iodine intake. Knowledge and awareness about the importance of iodine in nutrition and health can have a positive impact on the use of iodised salt. Therefore, the aim of this study was to assess the knowledge about and use of iodised salt among university students in two European countries. Methods Data from two countries (Germany and Greece) were extracted from a multi-centre cross-sectional survey, conducted among non-nutrition science/non-medical students from October 2018 to April 2019. Results Among the 359 participants in Germany (35% females, median age: 22 years) and the 403 participants in Greece (51% females, median age: 21 years), 41% and 37%, respectively, reported use of iodised salt at home. Users and non-users did not differ by age, gender and Body Mass Index or general interest in nutrition in both cohorts. However, those who had a better knowledge about iodine and (iodised) salt or had previously attended nutrition classes were more likely to report iodised salt usage. Conclusion The results suggest that strengthening the imparting of nutritional information and additional education of young adults are needed and may improve knowledge about and usage of iodised salt.