Droplet impact on wettability patterned surfaces has gained immense traction in recent days not only because of the inherently complex flow dynamics involved in it but also for its widespread applications in the fields of energy, sustainability, technology development, and healthcare. When a spherical droplet of liquid impinges on a flat solid surface, either by releasing it from a height or by forcing it from a nozzle, the droplet first spreads and attains a pancake shape on the surface. In case of high impact droplets, crowning and breakups are also observed at the periphery of the liquid-pancake towards the end of the spreading phase. Depending upon the substrate wettability, the post-impact behavior of droplet changes. On a highly wettable surface, e.g., water on a clean glass surface, the pancake-shaped liquid pool remains pinned at its periphery. On the contrary, on a highly non-wettable surface, e.g., a silanized glass, the liquid-pancake would retract after attaining a maximum spread and the inbound mass of liquid from all directions on the plane would collide near the center, giving rise to a Worthington jet. Depending upon the impact velocity and the liquid repellency of the surface, the retracted liquid volume might even bounce back—totally or partially—from the surface. Selective tuning of the substrate wettability, achieved either by altering its surface roughness and/or energy, or through modifying the liquid surface tension via addition of surfactants and/or nanoparticles, gives the user the latitude to realize different droplet impact behaviors to suit specific applications like inkjet printing, droplet impingement cooling of hot surfaces, spray painting and coating, or even point-of-care diagnostic devices. Other significant properties like substrate porosity, temperature and dust coverage also cause interesting changes in the impact dynamics due to their influence on the solid–liquid interactions during the droplet impingement. This chapter will highlight a subset of the multidimensional parametric regime of droplet impact dynamics that are pertinent to thermal management, energy and water harvesting, and for point-of-care diagnostic devices. The intricate interplay between the inertial, capillary and viscous forces is unraveled through discussion of a few novel droplet impingement behaviors on wettability-engineered surfaces and elucidating the rationale of their deployment for select engineering applications.