This study investigated the effect of tax education on tax avoidance in Uganda, with a focus on taxpayers in Mbarara City. Three objectives guided the study: to assess the effect of tax knowledge on taxpayers' compliance behaviour, to examine the influence of tax awareness campaigns on tax avoidance rates, and to determine the relationship between taxpayer attitudes toward the tax system and avoidance tendencies. A cross-sectional descriptive survey was conducted with 150 respondents comprising individual taxpayers, SME operators, and tax professionals in Mbarara City. Data were collected using structured questionnaires and were supplemented by Uganda Revenue Authority administrative records for the period 2019–2023. Analysis was performed using descriptive statistics, Pearson correlation, and binary logistic regression. Results indicated that tax knowledge significantly reduced tax avoidance behaviour (β = −0.412, p < 0.001), tax awareness campaigns were significantly associated with reduced avoidance tendencies (OR = 0.44, p < 0.01), and positive taxpayer attitudes toward the tax system were negatively correlated with avoidance behaviour (r = −0.58, p < 0.001). The study concluded that strategic investment in tax education significantly curtailed tax avoidance in Mbarara City. The study recommended enhanced URA taxpayer education programmes, incorporation of tax literacy into formal education curricula, and improved transparency in public expenditure to cultivate positive taxpayer attitudes.