Zinc oxide is a promising semiconductor film for active devices on flexible substrates, and synthesis routes using nanoparticle inks enable greater variety of applications. We introduce and characterize a two-step transient laser annealing process to create fully densified zinc oxide films from nanoparticle ink precursors. A low temperature sub-millisecond calcining step to remove solvent and organic stabilizing ligands was followed by a high-temperature pulsed laser sintering step to form densified 50-100 nm thin films with resistivities of 10-1 to 10-3 Ω-cm. Film microstructures can be varied between crystalline and amorphous without significant film damage by adjusting the fluence of the high-temperature sintering step. These processes would be compatible with a variety of nanoparticle species, deposition methods, and patterning methods, including roll-to-roll processing paradigms.