Background: This study examined the prevalence of e-cigarette use (‘Vaping’) among university students and its associations with psychosocial correlates. Methods: 9,449 students received a 156-item anonymous online survey which assessed the use of e-cigarettes (ever or past year), alcohol and drug use, mental health issues, and impulsive and compulsive traits. Results: 3,572 university students (57.1% female) responded to the survey. The prevalence of past 12-month e-cigarette use was 9.2%, with 9.8% reporting having used more than 12 months ago. E-cigarette use was associated with the use of multiple other drugs (e.g., alcohol, opiates). Those who used e-cigarettes were significantly more likely to have mental health histories of ADHD, PTSD, gambling disorder, and anxiety, report low self-esteem, and endorse traits of impulsivity. Conclusion: Use of e-cigarettes is common in university students and appears to be associated with a variety of mental health and drug use problems. Clinicians should be aware that certain mental health conditions are more common in e-cigarette users. This study indicates the need for longitudinal research into the effects of chronic nicotine consumption on brain function and mental health, especially in young people, since such effects would be common to conventional tobacco smoking and vaping.