The calculation of the linear optical absorption (OA) coefficients is carried out in a δ-doped AlGaAs/GaAs triple-quantum well (δ-TQW) under the effects of an external electric and magnetic fields. We use a δ-doping at the middle of each quantum well. The effects of δ-doping on the energy transitions and OA of the δ-TQW are also discussed. The optical response is calculated in the framework of the intersubband transitions model and the rotating wave approximation. The OA coefficients are significantly dependent on the values of the different input parameters. The results are given as functions of the δ-doping at the single quantum well and of the electric and magnetic field strengths. The responses are tuned in the regime of the mid-infrared electromagnetic spectrum.