The development of eutectic Ga–In alloy liquid-metal particles (EGaIn LM Ps) represents a significant advancement in the field of materials science because of their low melting points and desirable properties, including thermal and electrical conductivity, conformability, and biocompatibility. However, the traditional technique for synthesizing EGaIn LM Ps via ultrasonication in aqueous media results in notable surface oxidation, which can degrade their properties, such as stability, size uniformity, flexibility, and conductivity, and consequently, restrict their potential uses. This paper presents a novel ultrasonication-based fabrication method for EGaIn LM Ps in carbonated water to reduce their oxidation. Smaller particles that exhibited notably lower oxide formation were generated without stabilizing polymers or surfactant chemicals, even in water-based surroundings. Moreover, the oxidation inhibition mechanisms of carbonated ions as scavengers of •OH radicals during ultrasonication were revealed, highlighting the promising applications of EGaIn LM Ps in aqueous media.