BACKGROUND: Suicide attempts and non-suicidal self-harm (NSSH) are major public health concerns that affect millions of young people worldwide. Consequently, there is a strong need for up-to-date epidemiological data in this population.AimsTo provide prevalence and trend estimates of suicidal thoughts and behaviours and NSSH thoughts and behaviour in university students. METHOD: Data are from a 2018 national health survey for higher education in Norway. A total of 50 054 full-time students (69.1% women) aged 18-35 years participated (response rate 31%). Suicidal ideation, suicide attempts and NSSH were assessed with three items drawn from the Adult Psychiatric Morbidity Survey, and thoughts of NSSH were assessed with one item from the Child and Adolescent Self-Harm in Europe study. RESULTS: Lifetime suicidal thoughts were reported by 21.0%, and 7.2% reported having such thoughts within the past year. In total, 4.2% reported a suicide attempt, of whom 0.4% reported attempting suicide within the past year. The prevalence of lifetime NSSH behaviour and thoughts was 19.6% and 22.6%, respectively. All four suicidal behaviour and NSSH variables were more common among students who were single, living alone and with a low annual income, as well as among immigrants. There was an increase in suicidal thoughts from 2010 (7.7%) to 2018 (11.4%), which was evident in both men and women. CONCLUSIONS: The observed high and increasing prevalence of suicidal thoughts and NSSH among college and university students is alarming, underscoring the need for further research, preferably registry-linked studies, to confirm whether the reported prevalence is representative of the student population as a whole.Declaration of interestNone.