The present disclosure provides for light delivery assemblies and, more particularly to light delivery assemblies/systems that provide light to and/or illuminate/treat predetermined locations (e.g., surgical sites), and related methods of use. An exemplary light delivery assembly (e.g., a surgical site light) includes a shell/housing (e.g., a plastic shell/housing) with a cross-sectional shape similar to an inward-facing asymmetrical C. The shell/housing is shaped to be placed proximal to a site (e.g., surgical site) and emit light onto the site from a plurality of directions while inhibiting the light from radiating away from the outside of the shell/housing. Exemplary light delivery assemblies of the present disclosure can be utilized for a variety of different applications/treatments/uses (e.g., surgical applications, disinfection/sterilization especially UV in the UVC wavelength range, other UV treatment, infrared heating and treatment, therapy, IR light delivery, use of all/other wavelengths of light, etc.).