A bright millisecond radio burst of extragalactic origin was discovered by analyzing archival data from a 1.4-GHz survey of the Magellanic Clouds using the Parkes radio telescope. The burst, with a flux of 30 ± 10 Jy, was detected in three neighboring beams and is located three degrees south of the center of the Small Magellanic Cloud (SMC). The burst properties suggest it is not associated with the Milky Way or the SMC, and current models indicate it is less than 1 Gpc away. No further bursts were detected in subsequent observations, implying it was a singular event, possibly a supernova or coalescence of relativistic objects. The burst exhibits a quadratic delay as a function of frequency, consistent with dispersion by a cold ionized plasma. The pulse width evolves with frequency, consistent with interstellar scattering. The burst's high energy output and lack of repetition suggest it is a new phenomenon. The burst's high flux and unique characteristics make it unlikely to be terrestrial in origin. The burst's high dispersion measure (DM) and location outside known SMC emission contours suggest it is beyond the SMC, at least 61 kpc away. The burst's distance is estimated to be less than 1 Gpc based on DM measurements. It is unlikely to be a gamma-ray burst or supernova at this epoch. The burst's properties make it a potential cosmological probe, with implications for the intergalactic medium. The burst's brightness temperature and energy suggest a compact source, possibly a relativistic jet or a highly energetic event. The burst is not associated with any known radio pulsars in the SMC or Milky Way. It is a unique event, possibly a new class of radio source. The burst's high flux and energy suggest it could be a rare standard candle, with potential for studying the ionized intergalactic medium at cosmological distances. The burst's discovery highlights the importance of pulsar surveys in detecting transient radio sources and understanding astrophysical phenomena. The burst's properties and location suggest it is a rare and significant event, offering insights into high-energy astrophysical processes.A bright millisecond radio burst of extragalactic origin was discovered by analyzing archival data from a 1.4-GHz survey of the Magellanic Clouds using the Parkes radio telescope. The burst, with a flux of 30 ± 10 Jy, was detected in three neighboring beams and is located three degrees south of the center of the Small Magellanic Cloud (SMC). The burst properties suggest it is not associated with the Milky Way or the SMC, and current models indicate it is less than 1 Gpc away. No further bursts were detected in subsequent observations, implying it was a singular event, possibly a supernova or coalescence of relativistic objects. The burst exhibits a quadratic delay as a function of frequency, consistent with dispersion by a cold ionized plasma. The pulse width evolves with frequency, consistent with interstellar scattering. The burst's high energy output and lack of repetition suggest it is a new phenomenon. The burst's high flux and unique characteristics make it unlikely to be terrestrial in origin. The burst's high dispersion measure (DM) and location outside known SMC emission contours suggest it is beyond the SMC, at least 61 kpc away. The burst's distance is estimated to be less than 1 Gpc based on DM measurements. It is unlikely to be a gamma-ray burst or supernova at this epoch. The burst's properties make it a potential cosmological probe, with implications for the intergalactic medium. The burst's brightness temperature and energy suggest a compact source, possibly a relativistic jet or a highly energetic event. The burst is not associated with any known radio pulsars in the SMC or Milky Way. It is a unique event, possibly a new class of radio source. The burst's high flux and energy suggest it could be a rare standard candle, with potential for studying the ionized intergalactic medium at cosmological distances. The burst's discovery highlights the importance of pulsar surveys in detecting transient radio sources and understanding astrophysical phenomena. The burst's properties and location suggest it is a rare and significant event, offering insights into high-energy astrophysical processes.