Crosby is a census-designated place in Harris County, Texas, United States. The population was 2,299 at the 2010 census.
Humphrey Jackson (1784–1833) moved to Texas from Louisiana in September 1823 and built a log cabin outside Austin's colony on the San Jacinto River, 0.5 miles (800 m) west of the site of present-day Crosby. On August 16, 1824, the Baron de Bastrop granted him title to a league and a labor of land, including the place where he had settled, in what is now Harris County. Jackson next petitioned the Mexican government to form the San Jacinto District under control of the Austin colony; he was elected alcalde of the new district in 1824, 1825, and 1827, and served as ex officio militia captain of the San Jacinto area. Jackson was buried at Crosby. Jackson's Bayou in eastern Harris County is probably named for him.Near what is now the Southern Pacific Railroad, the town was named for G.J. Crosby, a railroad construction engineer. In 1861, the Sabine and Galveston Bay Railroad and Lumber Company installed tracks through this site.