Resistive random access memory (RRAM) is considered a promising next-generation memory device owing to its low energy consumption and ultra-high speed. In this study, we demonstrated a vacuum-free and low-cost solution to fabricate a highly stable nonvolatile RRAM device. Organic materials such P3HT and PEDOT:PSS were used to form the active layer and top electrode, respectively. The fabricated organic RRAM has a structure of ITO/P3HT/PEDOT:PSS, and exhibits well-controlled and highly stabilized nonvolatile butterfly shape resistive switching behavior, with an endurance of up to 1000 repeated cycling tests. Schottky emission, hopping, and direct tunneling were evaluated for switching mechanism. The geometrical structure was analyzed using the field emission scanning electron microscopy image, and the switching mechanisms were confirmed through the ultraviolet photoelectron spectroscopy measurement and energy band diagram analysis. Our results indicate that the fabricated solution-processed organic RRAM devices have the potential for use in nonvolatile memory devices.