It is demonstrated that carbon quantum dots derived from curcumin (Cur‐CQDs) through one‐step dry heating are effective antiviral agents against enterovirus 71 (EV71). The surface properties of Cur‐CQDs, as well as their antiviral activity, are highly dependent on the heating temperature during synthesis. The one‐step heating of curcumin at 180 °C preserves many of the moieties of polymeric curcumin on the surfaces of the as‐synthesized Cur‐CQDs, resulting in superior antiviral characteristics. It is proposed that curcumin undergoes a series of structural changes through dehydration, polymerization, and carbonization to form core–shell CQDs whose surfaces remain a pyrolytic curcumin‐like polymer, boosting the antiviral activity. The results reveal that curcumin possesses insignificant inhibitory activity against EV71 infection in RD cells half‐maximal effective concentration (EC50) >200 µg mL−1 but exhibits high cytotoxicity toward RD cells (half‐maximal cytotoxic concentration (CC50) <13 µg mL−1). The EC50 (0.2 µg mL−1) and CC50 (452.2 µg mL−1) of Cur‐CQDs are >1000‐fold lower and >34‐fold higher, respectively, than those of curcumin, demonstrating their far superior antiviral capabilities and high biocompatibility. In vivo, intraperitoneal administration of Cur‐CQDs significantly decreases mortality and provides protection against virus‐induced hind‐limb paralysis in new‐born mice challenged with a lethal dose of EV71. Biocarbon quantum dots: a simple one‐step dry heating allows the synthesis of carbon quantum dots derived from curcumin. The obtained carbon quantum dots possess strong antiviral activity against enterovirus 71 through different mechanisms.