Transition metal dichalcogenide(TMDC) monolayers are atomically thin semiconductor materials of MX2 type, where M is the metal and X is the chalcogenide, that have similar honeycomb structure to graphene and exhibit unique electrical, thermal, and optical properties. Through substitution, the material properties can be controlled and optimized. This work offers an extensive investigation into the effects of different metal-site dopants (Mo, Ni, Sc, Ti, V, and W) on 2D-MX2 (M = Mo or W, X = S, Se, or Te). Utilizing computational modeling, the structural, electrical, and thermal properties of these materials were analyzed with a density functional theory based approach. Studying many different types of doped TMDC monolayers allows a better understanding how to control the properties of these promising materials.