We propose a precessing transient magnetar model for the recently discovered radio source GLEAM-X J162759.5-523504.3. We identify the observed period of ∼ 1 ks as the precession period of the magnetar deformed due to its strong (B φ ∼ 10 16 G) toroidal field. The resulting deformation of order 10 −4 implies a spin period of P s = 0.1 s. Assuming a strong dipole field of B d ∼ 10 14 G we predict a period derivative of Ṗs ∼ 10 −11 s s −1 . We also predict that the precession period of the magnetar can be observed in the hard X-ray band just as the other three galactic magnetars exhibit precession.