Light-to-moderate intensity strength training (LMST) improves muscular strength, physical functioning, and some side effects in head and neck cancer survivors (HNCS). Heavy lifting strength training (HLST) may further improve these outcomes; however, it has not been studied in HNCS. The primary aim of the LIFTING trial was to examine the feasibility and safety of a HLST program in HNCS ≥1-year post-surgical neck dissection. In this single-arm feasibility study, HNCS were asked to complete a twice weekly, 12-week, supervised HLST program, gradually progressing to lifting heavy loads of 80-90% of 1 repetition maximum (1RM) for barbell squat, bench press, and deadlift. The feasibility outcomes included recruitment rate, 1RM completion rate, program adherence, barriers, and motivation. The preliminary efficacy outcomes included changes in upper and lower body strength. Nine HNCS were recruited over an 8-month period during the COVID-19 pandemic. All 9 (100%) completed the 1RM tests and successfully progressed to heavy loads at approximately 5 weeks. The median attendance was 95.8% (range 71-100%), and few barriers were reported. Weight lifted increased for squat/leg press (median change: +34kg; 95% CI +25 to +47), bench press (median change: +6kg; 95% CI +2 to +10), and deadlift (median change: +12kg; 95% CI +7 to +24). No adverse events were reported and participants were motivated to continue HLST after the study. HLST appears feasible and safe for HNCS and may result in meaningful improvements in muscular strength. Future research should consider additional recruitment strategies and compare HLST to LMST in this understudied survivor population. NCT04554667.