This study investigates the impact of human capital development on economic performance in Nigeria, distinguishing between aggregate economic growth and individual economic welfare. Unlike much of the existing literature that treats economic growth and welfare as synonymous, the study adopts a dual-model Autoregressive Distributed Lag (ARDL) framework in which real GDP growth rate and per capita income are specified as separate dependent variables. Human capital is proxied by government expenditure on education, government expenditure on health, and tertiary enrolment rate, using annual time-series data for Nigeria from 1990 to 2023. The ARDL short-run results reveal that government expenditure on education and health exerts a positive and statistically significant effect on real GDP growth, while tertiary enrolment rate negatively affects growth. However, in the long run, education and health expenditures become statistically insignificant, and tertiary enrolment remains negative but insignificant, indicating weak long-term growth transmission. In contrast, the welfare model shows that government expenditure on education and health has a negative and significant effect on per capita income in both the short and long run, whereas tertiary enrolment rate positively and significantly influences per capita income. The findings highlight a clear divergence between growth and welfare outcomes of human capital development in Nigeria. While public human capital investment stimulates short-term economic growth, it fails to deliver sustained growth and broad-based welfare gains. Conversely, higher education enhances individual income prospects despite its weak contribution to aggregate growth. These results underscore the need for efficiency-oriented human capital policies and structural reforms that align education outcomes with labour market absorption to promote inclusive and sustainable economic development.