Despite the large number of studies, the reported resistive responses of GO/rGO-based materials to humidity deviate and can vary from n-type to p-type, including mixed responses with conversions from n-to p-type behavior. The observed behavior often depends on the specific composition and structure of the material, with rGO commonly exhibiting p-type responses due to disruptions of the hole transport upon interaction with water as electron donor, and the more insulating GO often showing n-type behavior, due to water molecules inducing ionic conductivity. In most studies, rGO was obtained from GO by thermal treatment or by chemical reduction. In this regard, the combination of GO with TiO 2 nanocrystals (TNCs) offers numerous advantages: First, carboxylic acids -which are prominently present in GO -are known to strongly bind to TiO 2 surfaces, enabling the efficient fabrication of robust composites. Second, TNCs are photocatalytically active and can provide photo-generated electrons for the reduction of GO upon UV irradiation. The photocatalytic reduction of GO was first reported in 2008 by Williams et al. for a GO/TiO 2 suspension in ethanol as a hole scavenger. This method was further applied to composite thin films of GO/TiO 2 , enabling the photocatalytic patterning of rGO films. Additionally, in contrast to thermal or chemical reduction methods, the photocatalytic reduction allows controlling the degree of reduction by simply adjusting the illumination time as well as the selective removal of functional groups, which is of particular interest for tuning the affinity of the material towards polar analytes. Last, the incorporation of TNCs provides additional sorption sites for water molecules. Consequently, the photocatalytic reduction using TNCs is well-suited to develop hybrid GO-based resistive sensors with both, optimized electrical and sensing properties. For example, Lee et al. illuminated ethanolic suspensions of GO and spherical TNCs with UV light to photocatalytically reduce GO to rGO, and drop-casted the obtained composites onto electrode structures. They compared the resistive responses of the UV-treated and non-treated material towards reducing gases and reported switching from n-to p-type behavior after formation of rGO within the composite. Here, we present a comprehensive study into (GO/rGO)/TNC hybrid nanofilms and their tunability via photocatalytic reduction for resistive humidity sensing. First, we present a layer-by-layer spin-coating (LbL-SC) method for the fast and efficient fabrication of hybrid films comprising GO and titania nanorods (TNRs) or nanoplates (TNPs) on various substrates with adjustable composition and thickness. Then, we investigate the tunability of the electrical, optical, and structural properties of these hybrid films via the photocatalytic reduction of GO, by systematically varying the UV exposure time, TNC shape, size, concentration, and film thickness. The evolution of the film composition is analyzed by charge transport measurements, scanning electron microscopy (SEM), and x-ray photoelectron spectroscopy (XPS). Furthermore, we demonstrate the use of the method to fabricate photocatalytically patterned films and highlight their application as resistive humidity sensors with widely tunable response characteristics.