Sheridan is suing the network for $5.7 million in damages and $35,000 in sanctions. She said she was fired from the TV series in 2008 because she complained about creator Marc Cherry's allegedly abusive behavior toward her.
The case was previously heard and ended in a mistrial in March after the jury informed the judge they were "hopelessly deadlocked," 8-4. Nine jurors must agree in a civil verdict.
The California Court of Appeals denied Sheridan a retrial in September, determining she was not wrongfully fired from the television show.
Chief Justice Tani Cantil-Sakauye denied Sheridan's appeal of the September ruling Friday.
The actress is expected to go to court again to argue her firing was a labor-code violation, E! News reported.