Exercise training improves health-related physical fitness and patient-reported outcomes in cancer survivors, but few interventions have targeted colorectal cancer (CRC) survivors. This investigation aimed to determine the feasibility and efficacy of a 12-week supervised exercise training program for CRC survivors. Feasibility was assessed by tracking participant recruitment, loss to follow-up, assessment completion rates, participant evaluation, and adherence to the intervention. Efficacy was determined by changes in health-related physical fitness. Over a 1-year period, 72 of 351 (21%) CRC survivors screened were eligible for the study and 29 of the 72 (40%) were enrolled. Two participants were lost to follow-up (7%) and the completion rate for all study assessments was ≥93%. Mean adherence to the exercise intervention was 91% (standard deviation = ±18%), with a median of 98%. Participants rated the intervention positively (all items ≥ 6.6/7) and burden of testing low (all tests ≤ 2.4/7). Compared with baseline, CRC survivors showed improvements in peak oxygen uptake (mean change (MC) = +0.24 L·min(-1), p < 0.001), upper (MC = +7.0 kg, p < 0.001) and lower (MC = +26.5 kg, p < 0.001) body strength, waist circumference (MC = -2.1 cm, p = 0.005), sum of skinfolds (MC = -7.9 mm, p = 0.006), and trunk forward flexion (MC = +2.5 cm, p = 0.019). Exercise training was found to be feasible and improved many aspects of health-related physical fitness in CRC survivors that may be associated with improved quality of life and survival in these individuals.