The Aquaman star, 36, says the decision returned on June 1 in favour of Mr Depp was not supported by the evidence presented during the six-week trial.
In documents seen by The Press Association news agency, Ms Heard's lawyers also argue investigations should be made into "improper juror service".
Mr Depp sued his former partner over a 2018 article she wrote for The Washington Post about her experiences as a survivor of domestic abuse, which his lawyers said falsely accused him of being an abuser.
"The verdict is excessive as a matter of law in light of the evidence and law, and should be set aside," the documents stated.
"For all the reasons set forth above, and for the reasons set forth on the record during the hearings and at trial, in the Motions in Limine and Motions to Strike, Ms Heard respectfully requests this Court to set aside the jury verdict in favour of Mr Depp and against Ms Heard in its entirety, dismiss the complaint, or in the alternative, order a new trial.
"Ms Heard further requests this Court to investigate potential improper juror service and take appropriate action warranted by the results of the investigation."
The actress' lawyers claim one of the jurors during the trial was not properly vetted by the court and that information was "inconsistent".
"The information on the jury panel list appears to be inconsistent with the identity and demographics of one of the Jurors," the document, signed by Ms Heard's lawyer Elaine Bredehoft, says.
"Juror No 15 was apparently born in 1970, not 1945, as reported to and relied upon by the parties - including Ms Heard - in selecting a jury panel."
The filing added the damages awarded to Mr Depp following the verdict, which total $US15 million ($A22 million), were "excessive" and "indefensible".
The sum was subsequently reduced by judge Penney Azcarate to $US350,000 ($A510,000) under a state cap.
Ms Bredehoft previously vowed Ms Heard would appeal the decision in the lawsuit and has "excellent grounds" to do so, saying there was "so much" evidence that was not included during the trial.
Mr Depp said he felt "at peace" and was "truly humbled" after winning the lawsuit, adding his decision to pursue the case "was only made after considerable thought" and his goal was to "reveal the truth, regardless of the outcome".
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