<p>Digitalisation may induce a shift in economic structures towards advanced and cleaner industries, stimulating smart green growth across sectors and countries. Most existing studies examine the relationships between two variables, either economic growth and CO₂ emissions or digitalisation and CO₂ emissions/economic growth, without analysing the causalities among the three variables together. Furthermore, there are few studies examining Green Total Factor Productivity (GTFP) using a large sample of countries and their income groups. The present study aims to fill this gap by analysing the causal links between the three variables using panels of 164 countries and a sub-panel of countries based on their developmental levels for the period 2000–2020. The paper also estimates GTFP and the contribution of digitalisation to long-run economic growth. The study finds a cointegrating relationship between the three variables mentioned above, and its positive impact on emission reduction and economic growth. A 10% increase in digitalisation leads to a 0.774% and 0.796% reduction in CO₂ emissions in high-income group countries and lower-middle-income countries, respectively, and an increase of 0.425% in per capita income in the full sample of countries, and 0.819% in high-income, 1.26% in upper-middle-income, and 0.607% in low-income countries. The green output growth is largely driven by increasing GTFP rather than factor accumulation, indicating a transition from input-led to productivity-led green growth across the sample of countries.</p>