We report on the fabrication and characterization of ridge waveguides in lithium niobate thin films by diamond blade dicing. The lithium niobate thin films with a thickness of 1 µm were fabricated by bonding a He-implanted lithium niobate wafer to a SiO(2)-coated lithium niobate wafer and crystal ion slicing. Propagation losses of 1.2 dB/cm for TE and 2.8 dB/cm for TM polarization were measured at 1550 nm for a 9.28 mm long and 2.1 µm wide waveguide using the Fabry-Perot method.