Newborn screening (NBS) is one of the most impactful population-based public health programs, exemplifying the power of early detection and timely intervention in preventive medicine. Its primary goal is to identify metabolic and genetic disorders that are often asymptomatic at birth but can lead to serious morbidity or mortality if left untreated. NBS began in the 1960s, when Robert Guthrie introduced dried blood spot (DBS) collection and a bacterial inhibition assay to detect phenylketonuria (PKU). Following the success of PKU screening and treatment, NBS gradually expanded to include other conditions such as congenital hypothyroidism, galactosemia, maple syrup urine disease, congenital adrenal hyperplasia, and hemoglobinopathies—though each was added individually. The introduction of tandem mass spectrometry (MS/MS) in the 1990s transformed NBS by enabling simultaneous detection of multiple disorders from a single DBS sample. Advances in microfluidics and molecular techniques further enhance the capabilities of NBS. However, rapid expansion led to significant variability in NBS programs. To address this, the Recommended Uniform Screening Panel (RUSP) was established in 2006 and currently includes 38 core conditions and 26 secondary conditions. Emerging genomic technologies—such as targeted DNA panels, whole exome sequencing, and whole genome sequencing—are further expanding the scope of NBS, though challenges related to cost, ethics, and interpretation of uncertain findings persist. Artificial intelligence (AI) and machine learning offer new opportunities to enhance diagnostic accuracy and follow-up. Expanding NBS globally will require affordable, scalable technologies and ongoing collaboration across disciplines.