How do ethnic group divisions affect parties’ linkage strategies? The provision of private or local club goods favoring co-ethnics by politicians has been well documented in the literature. However, whether clientelism tends to be more widespread in ethnically highly fragmented societies has not been systematically examined. Utilizing a dataset that includes information on more than 450 parties in eighty competitive party systems, we show that the mere presence of multiple ethnic groups does not lead to more clientelistic exchange. Nevertheless, in countries characterized by high levels of economic inequality between politically relevant ethnic groups, parties are more likely to rely on clientelistic strategies to attract votes. In addition, this positive relationship between ethnic income inequality and clientelism is contingent on parties’ ties to ethnic social networks. Specifically, in ethnically unequal societies, parties that can rely on existing ethnic organizations particularly engage in clientelistic modes of electoral mobilization.