Materials with the desirable surface wettability are of key importance in diverse applications. However, most of the existing chemical processes used for surface wettability control are often energy-inefficient, pollute the environment, and rely on harsh processing conditions. Therefore, highly-selective, green, and low-cost alternative fabrication techniques are in urgent demand. Low-temperature plasma processing is one such promising approach that satisfies the above requirements. In this review, we present recent advances in plasma processing to control surface wettability for diverse emerging applications in the environment, energy, and biomedicine fields. The underlying mechanisms of the plasma surface engineering, key features of the fabrication processes, and water-surface interactions are discussed. This review aims to guide further development of the plasma processing to effectively control the surface wettability of various surfaces. This effort is poised to contribute to the development of advanced functional materials targeting a broad range of applications.