The objective of this research was to determine the profit-maximizing planting date and seeding rate for cotton production in the upper Mid-South. We used field trial data from Tennessee, Missouri, and Mississippi from 2016 to 2018 to estimate a cotton lint yield response function to planting date and planting population. A sensitivity analysis was conducted to compare the results for different cotton lint and seed prices. Additionally, we explored how optimal seeding rates change with late planting. We found the optimal planting date is consistent regardless of the cotton or seed price, but the optimal seeding rate depends on seed and cotton price. As seed prices increase, the optimal seeding rate decreases; and as cotton prices increase, the optimal seeding rate increases. In the case of late planting, a producer is better off using a lower seeding rate than would be optimal at an earlier planting date. These results demonstrate how prices impact planting decisions and inform producers on optimal planting dates and seeding rates to maximize profits.