Objectives: The primary aim of this study was to evaluate the preliminary efficacy and feasibility of an 8-week high-intensity interval training program (Uni-HIIT) for young adult students in a university setting. Design: Randomised controlled trial. Method: Uni-HIIT was conducted at the University of Newcastle, Australia (February-June, 2017). Participants were university students 18-25yrs (n = 53; 20.38 ± 1.88yrs) randomized into the Uni HIIT program (n = 26) or wait-list control (n = 27) condition. Participants were required to attend up to three HIIT sessions/week for 8-weeks which included a variety of aerobic and muscular fitness exercise combinations lasting 8–12 minutes (using 30:30 sec rest:work intervals). The primary outcome was cardio-respiratory fitness (CRF) (20mSRT), and secondary outcomes included muscular fitness (standing jump, push-ups), body composition (InBody), executive function (Trail Making Test), anxiety levels (State Trait Anxiety Inventory) and perceived stress (Perceived Stress Scale). Linear mixed models were used to analyse outcomes and Cohen's d effect sizes were calculated. Process evaluation measures of recruitment, retention, attendance and satisfaction were conducted. Results: A large significant group-by-time effect resulted for CRF [8.4 shuttles (95% CI(2.9-13.9), P = 0.004,d = 1.08] and muscular fitness [4.0 repetitions (95% CI(1.2-6.8), P = 0.006,d = 0.99], and moderate effect size was observed for Trail B [-5.9 seconds (95% CI(-11.8-0.1.0), P = 0.052, d = 0.63]. No significant intervention effects were found for body composition, standing jump, anxiety or perceived stress (P > 0.05). High ratings of participant satisfaction (4.73), enjoyment (4.54) and perceived value (4.54) were observed. Conclusion: This study demonstrates the efficacy and feasibility of delivering a novel HIIT program in the university setting.