Protein synthesis is the essential cellular process of translating the genetic code into the major structural and functional biomolecule of the cell: the protein. Eukaryotic translation is a dynamic molecular process choreographed by translation ribonucleoprotein (trRNP) complexes that assemble upon a messenger RNA (mRNA) and regulate its interaction with the bimolecular catalyst of this event, the ribosome. From their transcription, mRNAs assemble within dynamic RNA-protein structures that regulate their stability, processing, localization, and ultimately their translation. Ribonucleoprotein (RNP) complex is a term used to broadly define these RNA-protein assemblies. trRNP complexes specifically relate to dynamic mRNA-protein structures that coordinate the translation process. trRNPs are at the core of eukaryotic translation control. They are endowed with the ability to regulate the localization, conformation, and activation of mRNAs, all features that regulate engagement with the ribosome and generation of protein product. This review provides a comprehensive analysis of the trRNPs of eukaryotic translation control. Mechanisms known for regulating eukaryotic trRNP activity will be discussed with reference to their significance in cell biology. The importance of distinct trRNPs in selective translation control will be highlighted with a specific focus on the DExH/D-box RNA helicase trRNPs and those of unique RNA binding proteins. The outcome is an enhanced understanding and appreciation for the role of RNP biology in the regulation of protein synthesis.