In an increasingly ageing, multilingual, and digitalised society, there is still a lack of research on older adults' adoption and use of mobile technology for supporting their self-directed second language learning. In the present study, we investigated the extent to which seniors residing in Germany (aged 60+) engage in mobile-assisted language learning (MALL) and the factors encouraging or discouraging them from using language learning apps by conducting a web-based survey (n = 208) and a series of in-depth individual interviews (n = 22). Our results show that (1) participants were resistant to fully embrace the potential of MALL despite their active engagement in language learning and extensive use of digital technology, online resources, and mobile devices; and (2) self-perceived digital literacy and openness towards new developments are strong factors favouring the use of language learning apps in older adulthood. We interpret and discuss these results in the light of theoretical accounts of mobile learning and education in (older) adults, emphasising the need to consider the specific requirements of late-life learners in future implementations of language learning apps. Based on our results, we highlight several implications for designers and developers of such apps intended to facilitate full inclusion of seniors as mobile language learners.