The labor supply response to agricultural wages is critical to the viability of crop production in high-income countries, which hire a largely foreign farm work force, as well as in low-income countries, where domestic workers move off the farm as the agricultural transformation unfolds. Modeling agricultural labor supply is more challenging than modeling the supply of other agricultural inputs or of labor to other sectors of the economy owing to unique features of agricultural production and farm labor markets. Data and econometric challenges abound, and estimates of agricultural labor supply elasticities are sparse. This review explains the importance and challenges of modeling farm labor supply and describes researchers’ efforts to address these challenges. It summarizes estimates of agricultural labor supply elasticities over the last 80 years, provides insights into variation in these estimates, identifies priority areas for future research, and reviews the most influential empirical work related to this important topic.