Using digital technology to adapt to their host country is an integral part of social inclusion for migrant and refugee populations. However, researchers have not empirically examined how digital technology use may affect subjective well-being among migrant populations. This study aimed to examine the association between increased digital technology use, technological self-efficacy, and subjective well-being. Using the 2020 Digital Divide Survey in Korea, our sample consists of 6520 native South Koreans and 699 North Korean migrants aged 18 years and older. We examined the three-way interaction of technological self-efficacy and being North Korean migrants in the relationship between the increase in the use of five types of digital technology, technological self-efficacy, and subjective well-being, using hierarchical linear regressions. North Korean migrants were statistically lower than South Korean natives in all types of increased digital technology use. Moderation analysis showed that technological self-efficacy positively moderated the relationship between increased digital technology use and subjective well-being. A three-way interaction showed that this relationship was stronger in North Korean migrants for three types of utilization, networking, information sharing, and life services. Considering the potential benefits of technological self-efficacy for North Korean migrants and what psychosocial digital technology education would be considered.