A series of low-creep magnesium aluminate spinel refractories doped with 0–3 wt% Y₂O₃ were prepared by sintering at 1750 °C. The physical properties, especially the high-temperature properties of the refractories, were investigated. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) were applied to characterize the phases and microstructure of the refractories. The results indicated that yttrium aluminum garnet (YAG) could be in situ formed with the addition of Y₂O₃ in the spinel refractories. This stabilized the grain boundary of the spinel. The mechanical properties and high-temperature creep resistance of the spinel refractory could significantly be improved by the addition of Y₂O₃.