Rodney King has been charged with misdemeanor DUI -- stemming from his July 12 arrest in Riverside County, CA .... TMZ has learned.
TMZ broke the story ... King was pulled over after officers claim they witnessed Rodney committing "multiple infractions" behind the wheel. Cops eventually suspected he was under the influence ... and arrested him.
After the arrest, King told CNN he was under the influence of a "medical marijuana prescription."
If convicted, King -- who has a prior DUI convictionon his record -- could face some serious jail time.