We report on the ultraviolet to near-infrared supercontinuum generation in a 3-mm-long yttrium orthosilicate channel waveguide implanted by oxygen. The generated broadest spectrum spans 575 nm (at −30 dB points) from 430 to 1005 nm when pumping the waveguide at 800 nm and spans 115 nm (at −30 dB points) from 345 to 460 nm when pumping the waveguide at 400 nm, respectively. The nonlinear refractive index of the ion implanted region is quantified by fitting our spectra to nonlinear pulse propagation simulations around 800 nm. Our analysis shows that the nonlinear refractive index of yttrium orthosilicate waveguide after ion implantation and thermal treatment is about half the value of the bulk crystal. Our research findings indicate that ion implantation is a promising method to fabricate channel waveguides for low-threshold supercontinuum generation.