As Vietnam undergoes rapid economic transformation, upgrading quality of workplace training with adult learning approaches has become imperative. This conceptual review examines the relevance and applicability of Andragogy, Malcolm Knowles’ foundational theory, in Vietnamese organizations. A systematic literature search was conducted across Scopus, Web of Science, ERIC, and Google Scholar (2021–2025), followed by PRISMA-consistent appraisal of methodological transparency, peer-review status, and plausibility of replication. The synthesis shows that internationally, Andragogical designs consistently enhance learner engagement, satisfaction, and training transfer, while adoption in Vietnam remains limited due to hierarchical culture, resource constraints, and uneven organizational readiness. To address these gaps, the study develops a hypothesized causal mapping of barriers, mediators, and opportunities, and thereby proposes a three-level conceptual framework (policy–organization–trainer/learner). The contribution is threefold: (1) theoretically, by clarifying how cultural and structural factors mediate the transfer of Andragogy into non-Western contexts; (2) practically, by offering a framework for policymakers and enterprises to align incentives, build readiness, and upskill trainers; and (3) methodologically, by highlighting the need for longitudinal and sector-comparative research beyond descriptive case studies. Embedding Andragogy in sequenced, context-sensitive interventions is essential to building a workforce adaptable, motivated, and globally competitive.