This lecture note provides a tutorial review of nonAbelian discrete groups and presents applications to particle physics where discrete symmetries constitute an important principle for model building. While Abelian discrete symmetries are often imposed in order to control couplings for particle physicsparticularly model building beyond the standard modelnonAbelian discrete symmetries have been applied particularly to understand the threegeneration flavor structure. The nonAbelian discrete symmetries are indeed considered to be the most attractive choice for a flavor sector Model builders have tried to derive experimental values of quark and lepton masses mixing angles and CP phases on the assumption of nonAbelian discrete flavor symmetries of quarks and leptons yet lepton mixing has already been intensively discussed in this context as well.