Background: This study aimed to determine the effect of rumination and elder abuse levels on successful aging in elderly individuals. Methods: This descriptive-correlational study was conducted with older individuals (n = 297) in Ağrı, Turkey, between October 2021 and May 2022. SPSS-22 and R v.4.1.3 were used in the study. Analysis was done with machine learning and artificial neural networks. Results: In the study, the mean age of the older individuals was 67.49 ± 3.04. Statistical estimates showed the regression model to be significant and usable, F(2,294) = 116.659, P = 0.001. Elder abuse and ruminative thought levels together explained 43.9% of the total variance (R2 = 0.439) of successful aging. The regression model indicated that increases in both the elder abuse level (t = −3.672, P < 0.001) and the ruminative thought level (t = −12.771, P < 0.001) of participants caused a statistically significant decrease in the successful aging level. The combined elder abuse and ruminative thought levels had a greater effect on successful aging (Model 1: F = 45.321, Model 2: F = 116.659, R2 Change = 0.309). The R2 value of the Random Forest regression model was 0.529, showing that the independent variables could explain 52.92% of the variation in the dependent variable. According to the SHapley Additive exPlanation values, which show the contribution or importance of each variable in the estimation of the model, it was determined that the most important variables for estimating the Successful Aging Scale variable were ruminative thought style and elder abuse screening. Conclusions: Our study indicates that a decrease in the levels of rumination and elder abuse could lead to improvement in successful aging. Longitudinal studies on successful aging in older individuals are recommended.