Local public workers are central to implementing sustainable development policies at the local level, yet the determinants of their wage growth remain underexplored from a sustainability governance perspective. Building on the “decent work” agenda embedded in SDG 8, this study examines how political context, fiscal capacity, and local wage institutions combine to shape wage increases for local public workers (LPWs) in South Korea. Using fuzzy-set Qualitative Comparative Analysis (fsQCA) on 17 regional governments for 2018–2021, we test whether configurations of progressive local councils, fiscal capacity and autonomy, living-wage adoption, socio-economic context, and workforce composition are sufficient for high LPW wage growth. No single condition is necessary across years; instead, distinct pathways emerge. In 2018, high wage growth is associated with configurations combining progressive councils with larger LPW workforces and supportive socio-economic context. In 2020–2021, fiscal capacity and autonomy become more salient, with high wage growth occurring where stronger fiscal conditions align with either progressive politics or institutional wage standards. The findings highlight that sustainable wage governance is configurational and time-varying, implying that policy mixes should balance decent work, local fiscal sustainability, and equitable service capacity.