A differential pressure sensor module (100, 200) comprising: a base (108, 208) defining a sensor chamber with a sensor chamber inlet, the base (108, 208) also having a pair of process fluid pressure inlets (104, 106, 224, 254), each configured to receive a respective process fluid pressure (P1, P2); a differential pressure sensor (218, 300) disposed within the sensor chamber and having an inlet configured to receive a first process fluid pressure and provide a signal indicative of a difference between the first process fluid pressure and a sensor chamber pressure external to the differential pressure sensor (218, 300) within the sensor chamber; a pair of isolation diaphragms (230, 256) disposed in substantially the same plane, each sealing a respective process fluid pressure inlet (104, 106, 224, 254); a first fluid passageway fluidically coupled to one of the isolation diaphragms and the inlet of the differential pressure sensor (218, 300); a second fluid passageway fluidically coupled to the other of the isolation diaphragms and to the sensor chamber inlet; and an overpressure protection feature fluidically coupled to the sensor chamber, the first fluid passageway and the second fluid passageway, wherein the overpressure protection feature includes an overpressure protection diaphragm fluidically coupled to each of the first and second fluid passageways (258, 236) wherein the overpressure protection diaphragm is configured to a have a larger displacement than either of the isolating diaphragms (230, 256), and wherein the overpressure protection feature protects the differential pressure sensor (218, 300) when an overpressure is applied to either of the process fluid pressure inlets (104, 106, 224, 254). a base (108, 208) defining a sensor chamber with a sensor chamber inlet, the base (108, 208) also having a pair of process fluid pressure inlets (104, 106, 224, 254), each configured to receive a respective process fluid pressure (P1, P2); a differential pressure sensor (218, 300) disposed within the sensor chamber and having an inlet configured to receive a first process fluid pressure and provide a signal indicative of a difference between the first process fluid pressure and a sensor chamber pressure external to the differential pressure sensor (218, 300) within the sensor chamber; a pair of isolation diaphragms (230, 256) disposed in substantially the same plane, each sealing a respective process fluid pressure inlet (104, 106, 224, 254); a first fluid passageway fluidically coupled to one of the isolation diaphragms and the inlet of the differential pressure sensor (218, 300); a second fluid passageway fluidically coupled to the other of the isolation diaphragms and to the sensor chamber inlet; and an overpressure protection feature fluidically coupled to the sensor chamber, the first fluid passageway and the second fluid passageway, wherein the overpressure protection feature includes an overpressure protection diaphragm fluidically coupled to each of the first and second fluid passageways (258, 236) wherein the overpressure protection diaphragm is configured to a have a larger displacement than either of the isolating diaphragms (230, 256), and wherein the overpressure protection feature protects the differential pressure sensor (218, 300) when an overpressure is applied to either of the process fluid pressure inlets (104, 106, 224, 254).