AbstractWith two asynchronous frequency combs beating on a single detector, dual‐comb spectroscopy (DCS) enables rapid, broadband, and precise molecular fingerprinting on a comb tooth‐by‐tooth basis and thus holds much promise in molecular sensing. Sensitivity, however, has been an Achilles’ heel of this technique. Here, an approach for ultrasensitive nonlinear DCS based on plasmon‐enhanced coherent Raman spectroscopy (CRS) with ultrathin (100 nm) nanoporous gold films is presented. A high‐resolution (<8 cm−1) Raman spectrum is obtained within 32.8 µs for characterizing low‐density chemicals. The achieved sensitivity enhancement reaches ≈106–8 relative to nonenhanced dual‐comb CRS of liquid samples. The demonstrated approach may open up a new avenue for fast identification of trace amounts of chemicals.