Cancer vaccines are a promising strategic approach within the rapidly growing field of immuno-oncology. Therapeutic cancer vaccines are distinct from prophylactic vaccines and vary by both target antigen and vaccine platform. There are currently 3 FDA-approved therapeutic cancer vaccines: intravesical BCG live, sipuleucel-T, and T-VEC. Prior clinical trials have shown that vaccines are generally well tolerated, exhibit unique kinetics, can target tumor neoantigens, and induce antigen cascade. Ongoing clinical trials seek to improve vaccine efficacy either by targeting novel antigens or by combining vaccines with standard-of-care therapies or other immune therapies.