[en] Measurements are reported of the proton spin-lattice relaxation time T₁ in the tantalun--hydrogen system over the temperature and composition ranges, 77⁰K less than or equal to T less than or equal to 470⁰K and 0.155 less than or equal to H/Ta less than or equal to 0.677, respectively. In the high temperature, solid-solution (α) phase, the activation energy for hydrogen diffusion determined from the dipolar contribution to T₁, shows a weakly increasing trend from 0.134 eV/atom at H/Ta = 0.155 to 0.140 eV/atom at H/Ta = 0.677. Boundaries between ordered hydride phases and the α phase, located by the occurrence of abrupt changes in T₁, agree very well with other recent determinations. The quantity (T/sub 1e/T)/sup -1/2/, based on the conduction electron contribution, (T/sub le/)^-1, to the relaxation rate (T₁)^-1, is proportional to the density of states at the Fermi level N(E/sub F/). (T/sub 1e/T)/sup -1/2/ decreases linearly with increasing hydrogen concentration, similarly to its behavior in the V--H and Nb--H systems