Homelands are an integral component of nationalism. This recognition notwithstanding, the lines nationalism draws on the globe have received much less systematic attention than the lines drawn between in-groups and out-groups. This article argues that homelands, precisely because they are so central to nationalism, should be more consistently integrated into scholarship on international conflict, among other outcomes. We begin by detailing what homelands are, why they matter, and some suggested mechanisms for how they impact outcomes of interest. The next section considers the choices scholars make about identifying homelands, including the particular measurement strategy and the level of analysis used. Here, we highlight recent advances that enable the measurement and analysis of homelands in ways consistent with both constructivist insights about the possibility of variation in the homeland’s extent (both over time and within populations) and with positivist analysis. We conclude by sketching out future directions for research on homelands and nationalism.