We report the development of indium oxide (In2O3) transistors via a single step laser-induced photochemical conversion process of a sol-gel metal oxide precursor. Through careful optimization of the laser annealing conditions we demonstrated successful conversion of the precursor to In2O3 and its subsequent implementation in n-channel transistors with electron mobility up to 13 cm2/Vs. Importantly, the process does not require thermal annealing making it compatible with temperature sensitive materials such as plastic. On the other hand, the spatial conversion/densification of the sol-gel layer eliminates additional process steps associated with semiconductor patterning and hence significantly reduces fabrication complexity and cost. Our work demonstrates unambiguously that laser-induced photochemical conversion of sol-gel metal oxide precursors can be rapid and compatible with large-area electronics manufacturing.