40S ribosomal protein S5, also known as RPS5, is a ribosomal protein. Ribosomes, the organelles that catalyze protein synthesis, are composed of a small subunit and a large subunit that consist of over 80 distinct ribosomal proteins. RPS5 is a 204 amino acid component of the 40S complex. It exists as multiple processed pseudogenes that are scattered throughout the genome.