AbstractWe investigate the dynamics of the inner core wobble (ICW), the Euler‐Liouville wobbling motion of the Earth's solid inner core, under the mantle‐inner core gravitational (MICG) torques within the Earth. Chao (2016) derived the full 3‐D equation of motion for the MICG dynamics in terms of the spherical‐harmonic multipoles of mass density and focused on the axial component for inner core's torsional libration. Here aiming for the ICW, we deduce the 2‐D equatorial component of the MICG torque owing to the oblateness of the mantle and the inner core. The period of the free Eulerian wobble of a hypothetical isolated rigid inner core would be a prograde +414 days. The action of the added MICG equatorial torque is found to be (negatively) strong enough to render the wobbling motion to become retrograde (with a negative frequency), which is further but slightly modified by the elastic yielding feedback of the inner core. Imposing yet further the passive effect of the hydrostatic pressure due to the fluid outer core greatly lengthens the natural period to become decadal. The final estimate of the ICW natural period in accordance with the (seismological) PREM Earth model is a retrograde PICW ≈ −15.6 years, in contrast to a prograde +6.6 years supposed in the literature. The corresponding spring constant (per radian of wobble) is 5.5 × 1022 N m. Our results instigate likely identification of the ICW with decadal wobbles observed in the Earth's polar motion.