We have undertaken a survey of sub-stellar Y dwarf primaries with NIRCam on JWST in order to constrain properties of their multiplicity including orbital separation distribution, companion mass ratio distribution, and frequency. As the multiplicity properties of higher mass primaries appear to depend on host star mass, theories of multiple star formation can be put to a rigorous test by exploring these trends. Y dwarfs in the solar neighborhood represent an extreme in temperature, comprised of sub-stellar objects with low mass companions generated by fragmentation in the interstellar medium as well as perhaps planet formation. Here we report the discovery of a companion to WISE J033605.5-014350.4 at a projected separation of 0.075", position angle of 295 degrees, and with contrast of 2.7 and 1.2 magnitudes in F150W and F480M respectively. At a distance of 10 pc, assuming random inclination distribution the physical separation is about 1 AU. Assuming an age of 1-5 Gyr the companion mass is about 4-13 Jupiter masses, thus straddling close to the opacity limit for fragmentation, orbiting around this 7-19 Jupiter mass primary. Multiple pairs like the one discovered here, which can be assumed to have common formation age and composition, represent critical constraints on atmospheric as well as evolutionary theory of the formation and evolution of substellar companions.