Objectives: The landscape of work environments has undergone rapid transformation in the wake of the COVID-19 pandemic. This study aims to identify oral health issues among mobile platform workers, analyze the risk factors within their working environment, and promote their oral health. Methods: A purposive sampling approach was employed to select fifteen participants, including replacement drivers, delivery drivers, and delivery couriers/messengers operating within Seoul’s mobile platform workforce. In-depth interviews were conducted between August and November 2023, with all sessions recorded and transcribed. Utilizing grounded theory methodology, data analysis progressed through stages of open coding, axial coding, and selective coding, ultimately leading to the construction of a paradigm model. Results: The majority of participants were male (93.3%), with an average age of 58.7 years. The paradigm model revealed low tooth brushing rates among mobile platform workers. This phenomenon was attributed to a poor brushing environment and a lack of willingness to brush, with the related context being the poor working environment. Intervention conditions included support for tooth brushing, oral health education, and oral examinations. Implementing an action-interaction strategy, which involves problem-solving pathways and a strong motivation to improve, resulted in improved tooth brushing rates. Conclusions: To promote the oral health of mobile platform workers, it is essential to improve the environment for tooth brushing, particularly by increasing the availability of restrooms and related facilities as brushing spaces. Additionally, It is necessary to develop oral health policies and implement interventions based on an understanding of the working environment of mobile platform workers.