Although the genome of theStreptomycesmodel strainS. coelicolorwas sequenced nearly two decades ago, the function of many annotated genes has not been verified, including that of genesco1979, which was predicted to encode a transcriptional regulator of the xenobiotic response element (XRE) family. In this study, we showed that SCO1979 represses its own transcription and that deletion ofsco1979fromS. coelicolormarkedly enhanced production of three antibiotics, which are actinorhodin (ACT), undecylprodigiosin (RED), and calcium-dependent antibiotic (CDA), suggesting that SCO1979 represses their biosynthesis. We demonstrated that transcription of genes in the ACT, RED, and CDA pathways was generally increased in the mutant strain Delta 1979 compared with levels in the wild-type strain M145. Additionally, purified recombinant SCO1979 interacted with DNA sequences upstream ofsco1979andactII-orf4,redZ, andcdaR, the pathway-specific regulators for the three pathways, implying that SCO1979 potentially regulates the ACT, RED, and CDA pathways via their specific regulators. In addition, disruption ofsco1979led to the notably delayed formation of aerial mycelium and spores, and consistent with this, transcription of genes associated with aerial hyphae and spore formation, such aschpandrdl, andram, was reduced in Delta 1979, implying the involvement of SCO1979 in cellular development control as well. In summary, our findings demonstrated that SCO1979 is a pleiotropic regulator with roles in both secondary metabolism and morphological development inS. coelicolor.