This work presents for the first time the incorporation of graphene oxide/palladium nanoparticles composite into a carbon paste electrode and its application in the quantification of p‐nitrophenol, a very hazardous pollutant, in a synthetic wastewater sample. The composite presented a homogeneous particle distribution and narrow size distribution, averaging 4 nm. The resulting electrode presented improved shelf stability and prevented the adsorption of byproducts of p‐nitrophenol on the electrode surface, which is an advantage when compared to other sensors, due to the presence of the polymer polyvinylimidazole inside the graphene oxide matrix. This work also explores the performance of the proposed sensor among other dyes which can be present simultaneously in industrial wastewater and free water bodies.