The purpose of this study was to develop an ontology of intimate partnerships that can be used as a framework for collecting, processing, and analyzing big data of online posts written in Korean. An ontology is a group of words related to a certain topic domain that are grouped into a stratified structure. The scope of our ontology is various intimate partnerships and non-partnerships including singlehood, dating, cohabitation, domestic partnership, living apart together, (re)marriage, divorce, widowhood in terms of the formation, continuation, and dissolution of such partnerships. Based on Noy and McGuinness’ (2001) guidelines, we developed an ontology with two overarching classes: the dimensions of partnerships and the dimensions surrounding partnerships. The dimensions of partnerships included five classes: (a) dating, (b) marriage, (c) couple life, (d) voluntary singlehood and cohabitation, and (e) divorce and remarriage. The dimensions surrounding partnerships had four classes: (a) daily life, (b) micro factors, (c) macro factors, and (d) others. We also developed a diagram of the ontology to help understand the overall structure of the ontology. Future researchers can use our ontology of intimate partnerships as a conceptual framework and methodological tool to explore the trend of intimate partnerships in Korea. Our ontology can also be expanded to a broader topic domain or adapted to other cultures and languages.