Experience‐dependent critical period (CP) plasticity has been extensively studied in the visual cortex. Monocular deprivation during the CP affects ocular dominance, limits visual performance, and contributes to the pathological etiology of amblyopia. Neuregulin‐1 (NRG1) signaling through its tyrosine kinase receptor ErbB4 is essential for the normal development of the nervous system and has been linked to neuropsychiatric disorders such as schizophrenia. We discovered recently that NRG1/ErbB4 signaling in PV neurons is critical for the initiation of CP visual cortical plasticity by controlling excitatory synaptic inputs onto PV neurons and thus PV‐cell mediated cortical inhibition that occurs following visual deprivation. Building on this discovery, we review the existing literature of neuregulin signaling in developing and adult cortex and address the implication of NRG/ErbB4 signaling in visual cortical plasticity at the cellular and circuit levels. NRG‐directed research may lead to therapeutic approaches to reactivate plasticity in the adult cortex. This image is associated with Figure 2 in Grieco et al. in this issue. It is an artistic rendition of their image data illustrating enhanced local excitatory inputs to monocularly deprived PV neurons (white circles) with bath applied NRG1. The eye‐like overlay in black conveys that therapeutic intervention of NRG1/ErbB4 signaling can be developed to help treat critical period‐relevant disorders such as amblyopia. The review article of Grieco et al. addresses a novel and critical role of NRG1/ErbB4 in regulation of visual cortical critical period plasticity.