Antitumor immunotherapy for colorectal cancer has been studied at the bench and bedside for decades. Some clinical trials of cancer immunotherapy have demonstrated a potential benefit for patients with colorectal cancer, yet immunotherapy remains only an experimental option for this disease. Here, we review the major immunotherapeutic approaches currently under investigation for colorectal cancer, including cancer vaccines and adoptive cell therapy. Weakness and advantages of each strategy and progress in clinical trials will be described. Examination of previous and ongoing research in colorectal cancer therapy should define a path towards identification, approval, and mainstream adoption of colorectal cancer immunotherapeutics.