In this article, we propose and demonstrate a spectrum-to-space mapping principle for localizing multiple wireless nodes in a simultaneous and single-shot fashion at terahertz (THz) frequencies. Spectrum-to-space mapping is achieved through two dual-port chip integrated waveguide (CIW)-based leaky-wave antennas (LWAs). Interfacing with the two LWAs, we integrate two transmitting and receiving chains operating between 360- and 400-GHz range in a single chip realized in a 65-nm bulk CMOS process. Utilizing the carefully engineered dispersive nature of the LWA and its frequency-dependent radiation patterns, we create unique spectrum-to-space calibration maps for both 1-D and 2-D angular localizations. The measured one-shot localization error variance is less than 1° in 1-D space with 200-Hz-resolution bandwidth (BW) and less than 2° in 2-D space for a 20-Hz-resolution BW. The high-resolution nature of the localization principle in a single-shot fashion makes this approach attractive for multi-wireless node localization, link discovery, beam-forming, beam-management, and beam-optimization methods.