Coach Bill Self suspended Giles last month from practice and announced last week that he had been suspended from game action for the first semester.
University police issued Giles a ticket for misdemeanor battery Monday night for an incident involving a former girlfriend.
"We are not now making a judgment about guilt or innocence regarding this incident," Self said. "But this is yet another example of C.J. putting himself in a situation in which negative things can happen.
"C.J. was well aware of the consequences of another lapse in judgment," Self added. "We normally would let the judicial process play its course before dismissing someone, but C.J. has exhibited a pattern of irresponsible behavior and has left us no choice."
Giles played in 33 games last year and averaged 6.2 points and 4.8 rebounds.