Optical interface assemblies are provided. The optical interface assemblies include a first portion having a plurality of optical waveguides. The first portion is configured for mating engagement with an optical fiber connector. A second portion is mated to the first portion. The second portion is configured for mating engagement with an electronic substrate that includes an embedded waveguide assembly. The first and second portions are further configured so as to align the plurality of optical waveguides, at a first end of the first portion, with a plurality of corresponding waveguide cores of the embedded waveguide assembly. The first and second portions are further configured so as to align the plurality of optical waveguides, at a second end of the first portion, with a plurality of corresponding optical fibers in the optical fiber connector. Also provided are electronic assemblies and methods for coupling optical fibers with electronic substrate embedded waveguides.