He was stopped during a routine search at a jail checkpoint, and told authorities that he had drugs with him, a rep for the L.A. County Sheriff's office told CNN.
O'Neal, 24, is being held in custody on bail initially set at $25,000. His lawyer was not immediately available for comment.
The charge isn't the first for O'Neal. In October, he and his father were both charged with felony possession of methamphetamine. The two had been arrested a month earlier on suspicion of drug possession when authorities found methamphetamine in the elder O'Neal's bedroom during a routine home probation search, stemming from Redmond's 2007 DUI arrest.
In recent days, Fawcett has also been in the public eye, due to health issues. The actress was hospitalized for side effects related to her treatment for cancer.