BACKGROUND: There is evidence of increasing levels of loneliness in Norwegian young people before the COVID-19 pandemic. It is not clear how the COVID-19 pandemic, and the associated necessary restrictions, impacted on these trends. AIMS: To examine how loneliness in young people changed across the pandemic, how loneliness relates to demographic characteristics and how different pandemic restrictions impacted loneliness. METHOD: We analyzed data from three waves of a Norwegian national higher education student survey (the SHoT-study). Data was examined from 2018 from a total of 49,836 students, 2021 from 62,212 students, and from 2022 from 53,362 (response rates 31-35%). Loneliness was measured by The Three-Item Loneliness Scale (T-ILS). RESULTS: There was a sharp increase in loneliness from 2018 to 2021, and a reduction in levels of loneliness in 2022, although at increased levels compared to prior to the pandemic. Females consistently report higher levels of loneliness than males, with a larger difference during the peak of the pandemic. There were higher rates of loneliness in geographical regions with higher COVID rates and greater pandemic-related restrictions during 2021. Loneliness was lower among students reporting more days on campus in 2021 and for those with lectures on campus in 2022, both with dose-response associations. CONCLUSIONS: Loneliness is a major public health problem among young adults in higher education. Loneliness increased during the pandemic and has decreased but is still not back to pre-pandemic levels. The results suggest the importance of open campuses and in-person lectures, for increased social connectedness among young people.