Ceramic biomaterials have been investigated for several decades, but their potential biomedical applications in cancer therapy have been paid much less attentions, mainly due to their lack of related material functionality for combating the cancer. In this work, we report, for the first time, that MAX ceramic biomaterials exhibit the unique functionality for the photothermal ablation of cancer upon being exfoliated into ultrathin nanosheets within atomic thickness (MXene). As a paradigm, biocompatible Ti3C2 nanosheets (MXenes) were successfully synthesized based on a two-step exfoliation strategy of MAX phase Ti3AlC2 by the combined HF etching and TPAOH intercalation. Especially, the high photothermal-conversion efficiency and in vitro/in vivo photothermal ablation of tumor of Ti3C2 nanosheets (MXenes) were revealed and demonstrated, not only in the intravenous administration of soybean phospholipid modified Ti3C2 nanosheets but also in the localized intratumoral implantation of a phase-changeable PLGA/Ti3C2 organic–inorganic hybrid. This work promises the great potential of Ti3C2 nanosheets (MXenes) as a novel ceramic photothermal agent used for cancer therapy and may arouse much interest in exploring MXene-based ceramic biomaterials to benefit the biomedical applications.