We report the 1.03 μm and 1.05 μm laser operation of a diode-pumped Yb-doped YAG planar waveguide. The fabrication and characterisation of such multilayer planar waveguides by liquid phase epitaxy are also described. Diode-pumped laser results (≤ 43 mW threshold, ≥ 77% slope efficiency) obtained with 2.1% output coupling compare very favourably with results reported elsewhere for bulk lasers.