This study explored the relationship between digital taxation and e-commerce growth among informal traders at Kasita market in Kampala, Uganda. A quantitative research design was employed, drawing a sample of 136 traders through systematic random sampling from a population of 310. Digital taxation was conceptualized through three dimensions: digital tax awareness, tax compliance costs, and digital tax infrastructure. E-commerce growth was measured by online sales volume, digital customer base expansion, and digital payment adoption. Descriptive statistics, Pearson correlation, and regression analysis were conducted using SPSS v25. Results indicated a significant negative relationship between tax compliance costs and e-commerce growth (β = -0.312, p < 0.01) and a significant positive relationship between digital tax infrastructure and e-commerce growth (β = 0.398, p < 0.001). Overall, digital taxation explained 44.7% of the variance in e-commerce growth (R² = 0.447). The study recommends simplification of digital tax obligations and investment in affordable digital payment infrastructure for informal traders.