Purpose: This study aimed to identify possible patient- and tumor-related factors associated with risk of TNM stage III disease in nonmetastatic colon cancer. Methods: The associations between stage III disease and age, sex, lymph node yield, pathological tumor (pT) stage, tumor subsite, type of surgery, and priority of surgery were assessed in a nationwide cohort of 13,766 patients treated with curative resection of colon cancer. Each level of age, lymph node yield, and pT stage was compared to the preceding level. Results: Age, lymph node yield, pT stage, tumor subsite, and priority of surgery were associated with stage III disease. Odds ratios (95% confidence interval [CI]) were as follows: age < 65/65-75 years: 1.28 (95% CI, 1.15-1.43) and 65-75/ > 75 years: 1.22 (95% CI, 1.13-1.32); lymph node yield 0-5/6-11: 0.60 (95% CI, 0.50-0.72), lymph node yield 6-11/12-17: 0.84 (95% CI, 0.76-0.93), and lymph node yield 12-17/ ≥ 18: 0.97 (95% CI, 0.89-1.05); pT1/pT2: 0.74 (95% CI, 0.57-0.95), pT2/pT3: 0.35 (95% CI, 0.30-0.40), and pT3/pT4: 0.49 (95% CI, 0.47-0.54). Only tumors of the transverse colon were independently associated with lower risk of stage III disease than tumors in the sigmoid colon (sigmoid colon: 1, transverse colon: 0.84 [95% CI, 0.73-0.96]; elective surgery: 1, acute surgery: 1.43 [95% CI, 1.29-1.60]). Conclusion: In this study, stage III disease in colon cancer was significantly associated with age, lymph node yield, pT stage, tumor subsite, and priority of surgery but was not associated with right-sided location compared with stage I and II cancers.