All-solution-processed multifunctional organic bioelectronics composed of reduced graphene oxide (rGO) and dexamethasone 21-phosphate disodium salt (DEX)-loaded poly(3,4-ethylenedioxythiophene) (PEDOT) microelectrode arrays on indium tin oxide glass are reported. They can be used to manipulate the differentiation of human mesenchymal stem cells (hMSCs). In the devices, the rGO material functions as an adhesive coating to promote the adhesion and alignment of hMSC cells and to accelerate their osteogenic differentiation. The poly(L-lysine-graft-ethylene glycol) (PLL-g-PEG)-coated PEDOT electrodes serve as electroactive drug-releasing electrodes. In addition, the corresponding three-zone parallel devices operate as efficient drug-releasing components through spatial-temporal control of the release of the drug DEX from the PEDOT matrix. Such devices can be used for long-term cell culturing and controlled differentiation of hMSCs through electrical stimulation.