Ribosomal Protein S19, also known as RPS19, is a part of the S19E family of ribosomal proteins. RPS19 is located in the cytoplasm and required for pre-rRNA processing and maturation of 40S ribosomal subunits. Mutations in RPS19 trigger Diamond-Blackfan anemia, a constitutional erythroblastopenia characterized by absent or decreased erythroid precursors, in a subset of patients.