<p>Surface wettability, governed by the interplay of chemical composition, topography, and external stimuli, is a pivotal property influencing liquid–solid interactions across industries. This review explores cutting-edge advancements in surface engineering for wettability control, emphasizing innovations such as smart self-cleaning coatings, adaptive materials, and gradient topographies that dynamically respond to environmental cues. We systematically analyze the underlying mechanisms—ranging from chemical functionalization to physical nanostructuring—and their transformative applications in coatings, biomedical devices, electronics, and sustainable technologies. A key focus is placed on sustainability, highlighting eco-friendly modification techniques, biodegradable materials, and energy-efficient processes that align with global environmental goals. By integrating interdisciplinary insights from materials science, chemistry, and engineering, this work underscores the potential of tailored wettability to address pressing challenges in resource efficiency, healthcare, and industrial performance. Finally, we identify emerging trends, including machine learning-driven design and bio-inspired systems, while addressing scalability and durability limitations to guide future research. This comprehensive synthesis aims to bridge fundamental science with real-world applications, fostering innovation at the intersection of surface engineering and sustainability.</p>