This paper presents a compact and low-loss waveguide phase shifter based on a pin lattice in glide- symmetric configuration. There is a significant increase in provided phase shift when using a glide-symmetric pin distribution instead of a non-glide-symmetric configuration. A prototype has been manufactured to validate the simulated results of both phase shifters: non-glide-symmetric and glide- symmetric designs. Gap-waveguide technology has been implemented for low-cost manufacturing. The measurement results demonstrate the higher performance and compactness of the glide-symmetric phase shifter. For the same phase shifter length, the glide-symmetric design provides around 80 degrees more of phase shifting compared to the non-glide-symmetric phase shifter. Both phase shifters have a good impedance matching between 46 and 60 GHz (better than -10 dB) and an insertion loss lower than 1 dB.