An expanding body of evidence suggests that specifically targeting hydrogen sulfide (H2S) might potentially benefit both tumor diagnosis and treatment, but there is still a lack of cancer‐targeted molecular tools for in vivo applications. Here, we report the first ligand‐directed H2S‐specific near‐infrared fluorescent sensor PSMA‐Cy7‐NBD and scavenger PSMA‐Py‐NBD that target the prostate‐specific membrane antigen (PSMA). PSMA‐Cy7‐NBD displays a 53‐fold off–on fluorescence response to H2S at 803 nm with high specificity. PSMA‐Py‐NBD can scavenge H2S fast (