Digital literacy is increasingly recognized as being key to advancing the digital inclusion of adults across societies. While recent scholarship has illuminated the needs of adult learners seeking to acquire digital skills, less attention has been paid to the role played by people in the community who support adults’ digital learning. This study investigates the practice of ‘digital mentoring’ as a key enabler of adult digital literacy in community contexts in Australia. A co-design methodology, informed by a Community of Practice sociocultural approach, was applied to investigate how practising digital mentors work with members of the public to help them develop relevant digital skills. Through workshops, telephone interviews, and mind-mapping activities, the researchers and participants co-designed a Digital Mentor’s Handbook. This article extends this work by situating the applied research in national and international digital inclusion, adult learning, and community development scholarship and practice. Specifically, in the absence of existing explicit research on digital mentoring, this article builds on the scholarship of ‘mentoring’ more generally to propose both a definition of digital mentoring and eight principles of effective digital mentoring. The article’s contributions lie in providing one of the first scholarly accounts of digital mentoring as essential to advancing digital inclusion. It also presents eight principles of digital mentoring, packaged in a handbook, to help meet the changing, nuanced, and underserved needs of digital mentors in their communities.