Dedicator of cytokinesis protein 5 (Dock5) is a large protein encoded in the human by the DOCK5 gene, involved in intracellular signalling networks. It is a member of the DOCK-A subfamily of the DOCK family of guanine nucleotide exchange factors (GEFs) which function as activators of small G-proteins. Dock5 is predicted to activate the small G protein Rac.