Tubular T-joints are structural discontinuities that can be easily involved with stress concentrations. It is therefore necessary to estimate an internal stress distribution of T-joints. However, the complicated residual stresses are unavoidably produced adjacent to the joints by welding. In this paper, the residual stress distributions in welded tubular T-joints were analyzed by using a three-dimensional non-steady heat conduction analysis and a three-dimensional thermal elastic-plastic analysis. Characteristics of the residual stress distribution in welded tubular T-joints are investigated by the thermal-mechanical analysis results.