Background: Class III obesity (body mass index [BMI] ≥40 kg/m²) is increasing and perceived to increase technical complexity and morbidity post colorectal cancer (CRC) resection. Evidence specific to class III obesity, particularly from regional centres, remains limited. Methods: Retrospective cohort study of patients undergoing CRC surgery at Cairns Hospital from 25 February 2019 to 31 December 2025. Analyses were restricted to elective abdominal resections. Outcomes included operative approach (open or conversion vs completed laparoscopic), conversion among attempted laparoscopic cases, postoperative complications and oncologic quality metrics. Multivariable logistic regression adjusted for age, sex, ASA class (≥3), tumour location and neoadjuvant therapy. A systematic review of outcomes of class III obesity in CRC surgery and evidence for preoperative weight loss interventions. Results: Among 475 elective abdominal CRC resections, 29 (6.1%) patients had BMI ≥40 kg/m². Class III obesity patients were younger (median 59 vs 68 years) and more ASA ≥3 (89.7% vs 59.0%). Open or converted surgery occurred in 27.6% vs 14.3% (adjusted odds ratio [aOR] 1.90, 95%CI 0.76–4.72). Any postoperative complication occurred in 44.8% vs 26.5% (aOR 2.06, 95%CI 0.92–4.62). Surgical site/wound complications were higher in class III obesity (20.7% vs 3.8%; aOR 7.23, 95%CI 2.25–23.21), while anastomotic leak rates were similar. Length of stay and short-term mortality unchanged. The systematic review identified signals for higher wound complications and technical difficulty in severe obesity, mixed findings for overall morbidity; evidence for short preoperative weight loss is emerging. Conclusion: In our regional cohort, class III obesity was strongly associated with wound complications, signalling toward higher open conversion and overall morbidity. Targeted strategies and further evaluation of weight optimisation for patients with severe obesity undergoing CRC surgery are warranted.