Physical fitness is an important aspect of physical health and wellbeing. The aim of this study was to investigate the effects of 11-weeks of formal strength and conditioning training conducted during fire academy training on the physical fitness characteristics of firefighter trainees. Archived physical fitness data for 23 male fire academy trainees (age: 27.6 ± 4.3 y; height: 178.5 ± 6.9 cm; body mass [BM]: 83.9 ± 1.8 kg; BM index [BMI]: 26.8 ± 2.8 kg/m2) were analyzed for this study. These data included vertical jump height, maximum pull-up repetitions, hand grip strength, lower-body strength (3RM Hexbar) and aerobic fitness. Trainees performed three sessions per week (two resistance training sessions and one aerobic conditioning session) in addition to fire academy training. A repeated measures ANOVA revealed significant (p < 0.05) pre-post decreases in BM and BMI and significant increases in upper- and lower-body strength, and aerobic fitness. Strength and conditioning programs are beneficial for improving firefighter trainees’ physical fitness even when run concurrently with fire academy training and with limited space and equipment. This increased fitness may aid in mitigating known occupational injury risks to this population and improve task performance.