Chiral plasmonic nanostructures have attracted much attention due to their tunable chiroptical activity and biocompatibility, which offer them unprecedented opportunities in optical biological applications. Herein, we have synthesized chiral Au helicoids through a seed-mediated two-step growth and studied their photothermal inactivation effect on cancer cells under near infrared (NIR) circularly polarized light (CPL) irradiation. The as-prepared chiral Au helicoids show broadband optical absorption from 550 nm to 1100 nm and a high anisotropy factor. Under CPL irradiation at 808 nm, the photothermal inactivation efficiency of chiral Au helicoids on HeLa cells demonstrates a clear chirality dependence. L-Au helicoids demonstrate a much higher photothermal inactivation efficiency under left-CPL (L-CPL) than the D-Au helicoids under right-CPL (R-CPL), leading to an obvious chirality dependence in the death ratio of cancer cells. Further investigations indicate that chirality-dependent uptake of Au helicoids by HeLa cells partly contributes to the difference in photothermal inactivation efficiency on HeLa cells. Our findings demonstrate that the introduction of chiral plasmonic nanostructure into photothermal therapy can enhance the specific interactions of chiral nanomaterials with tumor cells and thus the photothermal inactivation efficiency.