The purpose of this study was to develop and validate a scale to measure the lifelong learning competence of adults in South Korea. This study followed the development and validation procedures of measurement tools proposed by Shin, Kim, & Kim (2009) and DeVellis (2003). Twenty-seven items of the lifelong learning competence scale of adults in South Korea, confirmed through a pilot survey, were validated through the main survey. The samples of the main survey were 799 adults over 19 years old. Construct validity, convergent validity, discriminant validity, cross validation, and criterion validity were analyzed with the collected data. There are major two conclusions. First, the scale for measuring the lifelong learning competence of adults in South Korea developed and validated in this study is a measurement tool that can measure ‘the basic learning competence required for adults living in modern society to live their daily lives'. Second, this scale consists of six competences of self-understanding, complex problem-solving, collaboration, correct decision-making, social change sensitivity, and self-directedness with 27 items.