Boron nitride has recently emerged as the platform of choice to study light-matter interaction at the nanoscale. So far, efforts have been dedicated to study hexagonal boron nitride (hBN)—as it has been shown to host bright quantum emitters. In this paper, López-Morales and colleagues report for the first time that also defects in cubic boron nitride (cBN), a cubic polymorph of BN, can act as quantum light sources. Like its hexagonal counterpart, cBN also possesses a large bandgap, which means it can host a plethora of optically active defects. The study shows the promising properties of these defects—including narrow linewidths and fast lifetime. The results are intriguing as the cubic symmetry of cBN is likely to host defects with symmetries resembling the nitrogen-vacancy center in diamond, and hence possess promising spin properties that can be harnessed for scalable quantum photonic applications.