In this dissertation, I describe the results of investigations into the influence of translation on protein folding in living cells. The environment in the cell differs greatly from that found in traditional experimental conditions for measuring protein folding in vitro. In the cell, protein folding is coupled to synthesis of the protein by the ribosome. The nascent polypeptide chain begins to fold as it emerges from the exit tunnel of the ribosome. This co-translational folding represents an important restriction on the conformational ensemble populated by nascent proteins in vivo. In this thesis three sets of investigations into the relationship between translation and protein folding are described. The first investigation reveals that a protein populates different conformations after folding co-translationally than it does in a variety of in vitro refolding conditions. The next investigation shows that small, genetically encoded changes in translation rate can predictably alter the folded state of a protein. This thesis shows for the first time that the co-translational molecular chaperone Trigger Factor can promote the formation of native folded structure by nascent polypeptides still associated with the ribosome. Investigations into the role of genetic elements that modulate translation on bacterial physiology are also described. The results presented in this thesis show that the coupling of protein folding to the process of translation is critical part of how nascent proteins reach their native structures in vivo.