In this study, we investigated the synchronization of coupled fractional-order Markovian reaction–diffusion neural networks (MRDNNs) with partly unknown transition rates. The novelty of this study lies in two aspects. First, the Markovian switching model and reaction–diffusion term are incorporated into a fractional order system, which is a difficult and uncommon problem in existing studies. The synchronization problem of fractional-order MRDNNs was solved by introducing a continuous frequency distribution model of a fractional integrator. Second, a new set of sufficient synchronization conditions with low conservativeness was derived. The (extended) Wirtinger inequality and delay-partitioning technologies were used to introduce generous free parameters, thereby effectively increasing the range of solutions. Through quantized control, the channel bandwidth and communication rate were reduced. Furthermore, a simulation was performed to illustrate the validity of the results and demonstrate the influence of fractional order and reaction–diffusion term on the synchronization rate of the system.