Assessment of digital competence for citizens could support the Education Action plan at a national level, a regional level, or even at a global level to enhance the digital skills and competence gap for work and life for digital transformation. This study applies the DigComp framework through a self-administered online survey to 723 citizens in Vietnam, using a sequential exploratory mixed methods research design. Data were analysed using factor analysis, standard descriptive statistics, and simple regression methods, followed by qualitative content analysis from interviews with ten respondents and a focus group discussion with eight stakeholders on digital competence. The results confirmed the validity of the DigComp framework for measuring the digital competence of Vietnamese citizens. Overall, the proficiency level of the 723 surveyed Vietnamese citizens falls between basic and intermediate levels, being more advanced in areas in information and data literacy and communication and collaboration, compared to digital content creation, safety, and problem solving. The results further showed that male citizens with a higher education level, working in the public sector, or living in province with high provincial digital transformation index rankings perceived themselves to be more digital competent than females with a lower educational level, working in the private sector, or living in the province with low provincial digital transformation index rankings. To improve citizens' digital competence, training should be designed that considers not only citizens' digital competence profiles but also their individual characteristics.