This study investigated whether attitudes, subjective norms, and perceived behavioral control regarding marriage were associated with marital intentions among unmarried young adults from single-person households in Seoul, based on the theory of planned behavior. We analyzed 460 unmarried Seoul residents between 20-39 years old who lived alone. The pooled dataset from the Seoul Family Survey, conducted in 2021 and 2022, was utilized. Multiple regression analyses showed that marital intentions were higher when the respondents were male, younger, and in a relationship. We also found that more positive attitudes toward marriage and a higher perceived likelihood of obtaining a stable job were associated with stronger marital intentions. These findings underscore the importance of addressing factors, such as attitudes toward marriage and perceptions of job stability when understanding young Korean adults’ intentions to marry.