Attorney who was introduced in episode 1x03 [Catch and Release] as Denny Crane's illegitimate son, the result of a one-night stand. Later, Denny revealed that Donny's mother had admitted long ago that the boy was not really his son although Denny continued to provide financial support from afar.

After Denny revealed to Donny that he was not his father, Donny took up the case of a man being sued by his ex-fiance because he left his wife at the altar in 1x15 [Tortured Souls]. Donny told Denny that he took the case to "beat your fat, lying ass". Denny denied it by saying that his ass may lie but it's all muscle. Donny lost the case due to his numerous outbreaks in court.

Donny also appeared in episode 2x25 [Squid Pro Quo], taking Denny on again in a lawsuit filed against the United States government. Once again, Donny was on the losing end.

Portrayed by Freddie Prinze, Jr.