Judge Tim Fox found nearly 240,000 violations under Arkansas' Medicaid-fraud law over Risperdal. Each violation came with a $5,000 fine, setting the total penalty at more than $1.1 billion.
Arkansas sued Johnson & Johnson and subsidiary Janssen Pharmaceuticals Inc. in 2007 over the drug.
Fox issued an additional $11 million fine in the Wednesday ruling for more than 4,500 violations under the state's deceptive practices act.
Previous Risperdal verdicts against J&J include a $327 million civil penalty in South Carolina.
Texas reached a $158 million settlement with Janssen in January.