We examine the impact of public sector salary disclosure laws on university faculty salaries in Canada. The laws, which enable public access to the salaries of individual faculty if they exceed specified thresholds, were introduced in different provinces at different times. Using detailed administrative data covering the majority of faculty in Canada, and an event-study research design that exploits within-province variation in exposure to the policy across institutions and academic departments, we find robust evidence that that the laws reduced the gender pay gap between men and women by approximately 30 percent. There is suggestive evidence that higher female salaries contributed to the narrowing of the gender gap. The reduction in the gender gap is primarily in universities where faculty are unionized.