Ribosome biogenesis is a key cellular process involving the assembly of ribosomal proteins with ribosomal RNA (rRNA) into the complex three-dimensional structure of mature ribosomes. This Special Issue features cutting-edge original research articles, as well as comprehensive reviews, covering various aspects of ribosomal protein involvement in ribosome assembly with a focus on the following areas: - Methods to investigate the role of ribosomal proteins in ribosome biogenesis;- The regulation of ribosomal protein synthesis;- The nuclear import of ribosomal proteins and ribosomal protein chaperones;- The functions of ribosomal proteins in rRNA folding;- The order and mechanisms of incorporation of ribosomal proteins into nascent ribosomes;- The importance of correct ribosome assembly for the function of the mature ribosome.