We report electrical tuning of spin relaxation in atomically thin T_(rm d)-MoTe₂, a representative low-symmetry transition metal dichalcogenide. Weak antilocalization measurements reveal strong spin–orbit interaction with spin–orbit lengths of tens of nanometers, consistent with recent theoretical predictions. Despite the semimetallic nature of T_(rm d)-MoTe₂, in the ultrathin limit the spin–orbit scattering time can be tuned electrostatically by up to threefold. We further investigate vertical electric field effects on the spin–orbit length and time, and demonstrate the modulation of the Rashba parameters. Relation between spin–orbit scattering time and the diffusion coefficient indicates that spin relaxation is governed by the D'yakonov–Perel' mechanism in both monolayer and bilayer T_(rm d)-MoTe₂. These results establish few-layer T_(rm d)-MoTe₂ as a platform for electrically tunable spin transport, thereby providing insight into spin relaxation in low-symmetry transition metal dichalcogenides.