Flavonoids are heterogeneous natural polyphenolic compounds, which are known to possess strong antioxidant, anti-inflammatory, anticancer, and neuroprotective activities. They have, however, shortcomings in clinical efficacy due to low aqueous solubility, low stability, and low bioavailability. The development of nanocarrier-based delivery systems has offered a hint of hope to counter these problems. Liposomes, niosomes, and polymeric nanoparticles, among other nanocarriers, have received a lot of attention, as they increase the solubility, preserve the flavonoids by preventing their degradation, and enhance the pharmacokinetic profile of flavonoids. Liposomes that are built up of phospholipid bilayers facilitate efficient encapsulation of both hydrophilic and lipophilic flavonoids. Nonionic surfactants are known as niosomes that are more stable and cost-effective than liposomes. Growth of flavonoids is controlled and sustained with polymeric nanoparticles synthesized using biodegradable polymers like poly(lactic-co-glycolic acid) (PLGA) or chitosan. This chapter addresses the design, preparation, characterization, and therapeutic uses of these nanocarriers and how they could be applicable in enhancing the delivery and bioefficacy of flavonoid-based therapeutics.