This review investigates the volunteering-work nexus, where an individual’s paid occupational work in the business, government, or voluntary sector is akin to their volunteer work: tasks and responsibilities are similar, but the structure, conditions, and relationships differ. Performing work spans their business and volunteer worlds and brings dynamic interactions between work and volunteering. Pro bono, skills-based, or corporate volunteering are terms in use; however, these conceptualizations of the underlying and interconnecting practices of work and volunteering are too limited. This transdisciplinary, qualitative systematic literature review of 62 scientific articles studies individuals using conceptualizations of work, volunteering, and occupations over their working life, from service-learning to retirement. With ambiguous boundaries and terminology in the literature, we introduce a new term— occupation-related volunteering—defined as an individual acting to benefit others without payment or coercion, developing, using, or maintaining their occupational knowledge, skills, and abilities, and drawing upon their economic, social, and cultural capital. The definition anticipates that an individual’s occupational resources change over their working life and vary depending on whether the volunteer is acting independently or with the support of their workplace. Occupation-related volunteering extends paid-unpaid and formal-informal boundaries to include volunteering in “paid” work time and in informal, community-based organizations and less public roles, such as mentoring. Finally, we encourage future research using the bibliometric data, suggestions in the reviewed articles, and our synthesis of the individual’s perspective of performing their occupational work as a volunteer.