Dendrimers are a class of well-defined, highly branched, multifunctional polymeric nanomaterials that have been largely studied as delivery platforms to target therapeutics or diagnostics to various sites of interest. In this chapter, we systematically describe the use of dendrimers for biomedical applications and how their physicochemical properties can be tuned to achieve desired outcomes in areas such as drug and gene delivery, anti-pathogen, and diagnostics. Furthermore, we introduce dendritic polymers and how their unique properties merge advantageous properties of dendrimers with other drug delivery platforms such as linear-block polymers and liposomes to improve biological responses. Several examples of the use of dendrimers and dendritic polymers will be detailed with the objective to reveal critical nanocarriers design features to achieve specific delivery goals. Although challenges still remain to be addressed to enable the clinical translation of this nanotechnology, it is clear that the future for dendritic nanomaterials is highly promising.