Monetary policy is conventionally understood to influence labor demand, with little effect on labor supply. Estimating the response of labor market flows to high-frequency changes in interest rates around FOMC announcements and Fed Chair speeches, we find that a contractionary monetary policy shock leads to a significant increase in labor supply, by reducing the rate at which workers quit jobs to non-employment and stimulating job-seeking behavior among the non-employed. Holding the response of supply-driven labor market flows constant, the overall decline in employment from a contractionary monetary policy shock becomes nearly twice as large.