Magnesium based spinel chalcogenides MgY(2)Z(4) (Z = S and Se) have recently become a focus of renewed research interest owing to their high magnesium mobility; making them potential candidates for Mg batteries. In addition, the existence of a >1 eV band gaps in MgY(2)Z(4) compounds also make them interesting for opto-electronic device operating in the visible to UV range of electromagnetic spectrum. Our calculations indicate that the electronic properties computed using the mBJ-LDA + SOC are in good agreement with earlier DFT calculations. The optical properties of the two compounds are examined as a function of incident photon energy, which indicate that these materials can be utilized in optical devices operating in visible and UV region of electromagnetic spectrum. The transport properties are also computed using BoltzTrap code where the variation of electrical conductivity, thermal conductivity and Seebeck coefficient with chemical potential and temperature is examined.