Affect labeling (putting feelings into words) decreases subjective emotional distress and is a form of incidental or unintentional emotion regulation. Anxiety is associated with deficits in explicit emotion regulation, but far less is known about incidental emotion regulation. This study examined whether participants with public speaking anxiety showed deficits in incidental emotion regulation compared to non-anxious participants. Ninety-five public speaking anxious and fifteen non-anxious participants completed an affect-labeling task. They viewed negative images, and on half of the trials, they labeled the content of the image, and on the other half, viewed the image without labeling. They then rated their subjective distress after each image. Following the affect-labeling task, participants gave a brief speech in front of a live audience. Physiological reactivity (heart rate and skin conductance) was assessed prior to and following the speech, and participants reported on speech-related cognitions and fear levels. Incidental emotion regulation deficits were significantly correlated with more depressive symptoms, and more negative and fewer positive speech-related cognitions during the speech task. Further, distress decreased on labeling compared to non-labeling trials for non-anxious participants, but not for participants with public speaking anxiety. This is the first study to show that individuals with public speaking anxiety may not benefit from affect labeling, implying deficits in incidental emotion regulation.