Understanding the origin of the elements remains one of the major challenges of modern astrophysics. Ultraviolet (UV) spectroscopy of metal-poor stars provides access to many absorption lines of elements and species that are otherwise undetectable in optical or infrared spectra. I will show how UV spectra collected with the Hubble Space Telescope have expanded stellar chemical inventories to more than 65 elements per star, identified signatures associated with r-process transuranic fission fragments, and provided new calibrations for NLTE radiative transfer calculations. I will also show how UV spectroscopy with the ANDES instrument on the Extremely Large Telescope and the proposed Habitable Worlds Observatory mission could revolutionize our understanding of the first stars in the decades ahead.