There are widespread concerns about the mental health implications of the pandemic, particularly among university students, an already at-risk population for poor mental health. This study looked at 1,281 UK university students, recruited through the Prolific website. Participants were asked to complete the Attitudes towards COVID-19 Scale, the CORE-10, the PERMA Profiler, the GAD-7 and the Office for National Statistics wellbeing questions (ONS4). The first survey was conducted between May 14th and 16th, when the UK was in national lockdown. The second survey was carried out between June 26th and July 15th. There was only an 11% attrition rate between the two time points. Well-being improved overall between the two time points. Some findings were contradictory as overall well-being, anxiety and levels of flourishing improved, but reports of psychological distress increased. It is also important to note that levels of positivity about the pandemic increased as time went on. There was evidence that higher levels of positivity were linked to better mental health outcomes. Encouraging a positive mindset and outlook in students, probably through positive psychology-based interventions, might act as a protective factor against severe mental illness. The wider relevance and practical implications for higher education are discussed.