Biological and non-biological pollutants are posing a major health and environmental threat worldwide. For this reason, we reported on the synthesis and investigations of the silver nanoparticle (ST-AgNPs), using Streptomyces thinghirensis sp. (ST) as an original Streptomyces species deposited in GenBank under the accession number DSM 41919 T. Various techniques such as UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, particle-size analyzer, scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM) for the characterization of the structure and morphology of biosynthesized ST-AgNPs, thereby, the evaluation of their catalyst and antimicrobial behaviors. ST-AgNPs nanoparticles are spherical, crystallizing with a size ranging from 10 to 30 nm, and are stable (−27.2 mV). They were able to reduce 4-nitrophenol to 4-aminophenol within 15 min. ST-AgNPs exhibited excellent antibacterial activities against Vancomycin-resistant Enterococcus faecium ATCC 700221vanA, Cefoxitin-resistant Staphylococcus aureus NCTC 12493 and Ceftazidime-resistant Pseudomonas aeruginosa ATCC BAA-2108, as well as Vancomycin-sensitive Enterococcus faecalis ATCC 29212, Cefoxitin-sensitive Staphylococcus aureus ATCC 29213 and Ceftazidime-sensitive Pseudomonas aeruginosa ATCC 27853, with the minimal inhibitory concentration ranging from 3.125 to 12.5 µg/mL. In conclusion the green synthesis approaches using ST would be the most important path in biomaterial sciences, which enrich their biological, medical and pharmaceutical applications.