Sense of belonging is an important topic in higher education. However, few studies have examined this important construct at the course level and in the online learning context; even fewer are quantitative by design. The aim of our study was to develop and evaluate a measure of sense of belonging that could be used across different postsecondary learning contexts. A psychometric investigation was conducted at a large, US southeastern university on data using the newly developed Brief Course Belonging Scale (BCBS). Results provide evidence for the unidimensional treatment of BCBS data across delivery context, convergent validity for BCBS scores as they relate positively to belonging at the university level, connectedness, and academic motivation, and discriminant validity for BCBS scores as they related minimally with loneliness. Differential item functioning was detected on one item, but this did not jeopardize score validity and reliability. Specific psychometric implications regarding the domain-specificity of the course delivery context as well as the administration of the novel instrument to a more broad, and diverse student population are recommended.