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The purpose of this study was to evaluate oxygen‐enhanced pulmonary imaging at 0.55 T with 3D stack‐of‐spirals ultrashort‐T_E (UTE) acquisition. Oxygen‐enhanced pulmonary MRI offers the measurement of regional lung ventilation and perfusion using inhaled oxygen as a contrast agent. Low‐field MRI systems equipped with contemporary hardware can provide high‐quality structural lung imaging by virtue of the prolonged T₂*. Fortuitously, the T₁ relaxivity of oxygen increases at lower field strengths, which is expected to improve the sensitivity of oxygen‐enhanced lung MRI. We implemented a breath‐held T₁‐weighted 3D stack‐of‐spirals UTE acquisition with a 7 ms spiral‐out readout. Measurement repeatability was assessed using five repetitions of oxygen‐enhanced lung imaging in healthy volunteers (n = 7). The signal intensity at both normoxia and hyperoxia was strongly dependent on lung tissue …