We demonstrate the first transverse magnetic (TM) pass waveguide polarizer suitable for integrated optic or fiber optic geometries. The polarizing properties of waveguides incorporating an ultrathin discontinuous silver film are due to excitation of a localized surface plasmon mode. The polarizers have a large bandwidth (≳100 nm), high extinction ratios, and do not rely on sensitive phase matching conditions. We illustrate these novel polarizing properties on ion-exchanged planar waveguides overlayed with a 5-nm-mass thick silver film. The measured extinction ratio was 35 dB/mm at 836 nm with 2 dB/mm loss for the TM polarization. The theoretical analysis of the film properties and waveguide propagation losses is compared with the experiments.