In-line back pressure fluid regulators are described. An example in-line fluid regulator includes a regulator body defining a sensing chamber and an outlet of a fluid flow path of the fluid regulator. The outlet is in fluid communication with the sensing chamber via a first flow passageway in the regulator body. A bonnet is coupled to the regulator body and defines an inlet of the fluid flow path and a loading chamber disposed between the sensing chamber and the inlet. The loading chamber is substantially sealed relative to the fluid flow path of the fluid regulator. A pressure sensor is disposed between the inlet and the sensing chamber, where the pressure sensor defines a second flow passageway to fluidly couple the inlet and the sensing chamber.