This study analyses the influence of controlling ownership, managerial ownership, and family ownership on tax aggressiveness in property and real estate companies listed on the Indonesia Stock Exchange (IDX) during the 2019-2023 period. Tax aggressiveness is measured using the Effective Tax Rate (ETR) proxy, defined as the ratio of income tax expense to pre-tax income, where a lower ETR reflects higher aggressiveness. The research population consists of 94 companies, with 18 firms selected through purposive sampling, yielding 90 firm-year observations. Secondary data were obtained from annual reports published on the IDX and the official company websites. Data analysis was conducted using multiple linear regression with IBM SPSS Statistics 25. The results reveal that controlling ownership, managerial ownership, and family ownership do not significantly affect tax aggressiveness. The coefficient of determination (R²) is 5.2%, indicating that the independent variables explain only a small proportion of the variation, while other factors such as profitability, leverage, and asset intensity may play a greater role. These findings suggest that ownership structure is not the primary determinant of tax aggressiveness. The implication for tax authorities is to consider broader financial and operational factors when formulating supervision strategies.