In the absence of historical income or education data, the change in occupations over time can be used as a measure of social mobility. This paper investigates intergenerational occupational mobility using a novel genealogical dataset for settler South Africa, spanning its transition from an agricultural to an early industrialized society (1800–1909). We identify fathers and sons for whom we have complete information on occupational attainment. We follow a two-generation discrete approach to measure changes in both absolute and relative mobility over time. Consistent with qualitative evidence of a shift away from agriculture as the economy’s dominant sector, we see the farming class shrinking and the skilled and professional classes growing. Controlling for changes in the structure of the labor market over time, we find increasing upward social mobility, becoming significant following the discovery of minerals in 1868. We find this mobility particularly for semi-skilled workers but virtually no improved mobility for sons of farmers. We also test hypotheses related to the mobility prospects for first-born sons and sons of immigrants.