Abstract Transition metal carbides, called MXenes, can be used for MXene‐based unique electronic devices such as new types of batteries, energy storage devices, and supercapacitors, where MXene is used as an electrode. The unique surface properties of MXene and 2D structure can be further applied to the new electronic devices. In this paper, the unique insulating properties of partially oxidized MXene (Ti 3 C 2 T x ) sheets are utilized for memory storage and electronic synapse applications. The device exhibits threshold resistive switching characteristics based on Ag + migration dynamics. It is found that this Ag + cation migration is similar to Ca 2+ ion dynamics of a biological synapse, and thus, biological synapse functions such as intrusion/extrusion of Ag + cation, paired‐pulse facilitation (PPF), post‐tetanic potentiation (PTP), short‐term potentiation (STP), and transition of STP to long‐term potentiation (LTP) are well‐emulated. It is believed that this device development can be potentially used in the next‐generation hardware‐based artificial intelligence systems.