Dendritic cells (DCs) are key antigen-presenting cells that connect innate and adaptive immunity, influencing tumor microenvironments by activating T cells, NK, and NKT cells, and directly killing tumor cells. They are being explored as immunotherapies in cancers like melanoma, breast, prostate, brain, and blood cancers with over 300 clinical trials to date. Intratumoral injection shows promise for its direct effects. The only FDA-approved DC therapy, sipuleucel-T, increases survival in prostate cancer. Further DC trials are ongoing, often combining DCs with other available immunotherapies. Early-stage disease is an emerging target for DC therapy. Further research is needed to optimize these approaches.