Any metal component failures (e.g., corrosion, fatigue) start from surface/subsurface defects (e.g., surface cracks, troughs, and pores). It is thus crucial to strengthen surface integrity by altering surface/subsurface properties in ways which provide protection from premature failure. To address this, in this paper, we presented a synergistic plasticity burnishing plus tumbling treatment to enhance the surface integrity and mechanical properties of cold-rolled AISI 304 steel alloys. A total of 304 steel specimens were ball-burnished, followed by a rotary tumbling process. The treated specimens were characterised in terms of surface roughness, 2D/3D topography hardness, and microstructures using laser confocal microscopy, SEM, a micro-hardness tester and EBSD analysis, respectively. Tensile tests were performed in accordance with ASTM standards to evaluate the Young’s modulus, yield strength, UTS and elongation. To evaluate the efficacy of the proposed synergistic approach, the results were compared and analysed across four types of specimens referred to as (1) “Untreated (as rolled)”, (2) “Burnished”, (3) “Tumbled” and (4) ‘Burnished+Tumbled”. The results showed that the ball burnishing resulted in grain modification and dislocation within the microstructure, improving the hardness and surface finish. But when the tumbling was applied to the burnished surface, the process augmented further hardness, grain modification, and yield strength, while there was a negligible impact on the fracture strength and elongation. These improved surface integrity properties are expected to enhance corrosion and fatigue life. The findings indicate that the combined burnishing–tumbling approach can extend the operational life of components subject to extreme loading conditions, thus saving huge costs by minimising premature failure.