This study investigated the effectiveness of PGP-Streptomyces in commercial greenhouses growing bell peppers. The strains tested increased green pepper yields by up to 26% and improved the sensory qualities of orange peppers. They also reduced nitrate levels by 32–41%, raised micronutrient content, and enhanced defense gene expression and antioxidant enzyme activity. These findings suggest that PGP-Streptomyces have significant potential for improving greenhouse pepper production.