We introduce a dataset that focuses on the delimitation of interstate borders under international law—the International Border Agreements Dataset (IBAD). This dataset contains information on the agents involved in (e.g. states, third-parties, and colonial powers), methods used during (e.g. negotiation, mediation, arbitration, adjudication, administrative decrees, post-war conferences, and plebiscites), and outcomes of (e.g. full and intermediate agreements) the border settlement process during the period 1816–2001. Our focus on international legal agreements and the process that produces them makes the IBAD valuable for those that study not only territorial conflict, but also international conflict, cooperation, law, and conflict management.