JACKSONVILLE, Fla. (AP) _ A newspaper ordered to pay $100,000 in damages for publishing a rape victim's name was within its constitutional rights and will appeal the decision, its publisher says.

Florida Star publisher Eric Simpson, who had testified that the woman's name was used by mistake, said he was ''amazed and dumbfounded'' by the verdict and award.

''We definitely will appeal,'' he said.

The Florida Star Inc. was sued by a woman whose name was obtained from a Jacksonville sheriff's office report and published in the Jacksonville weekly's police briefs column Oct. 29, 1983.

Circuit Judge John S. Cox ordered a jury Wednesday to find the Florida Star Inc. negligent for publishing the woman's name and to decide whether to award financial damages.

The jury awarded the woman $75,000 compensation and $25,000 in punitive damages. The woman also sued the sheriff's office, which settled out of court for $2,500.

The woman said she hoped the decision would discourage future publication of rape victims' names.

Under Florida law, it is a misdemeanor to publish or broadcast information that identifies a rape victim or to cause such information to be published.

But Simpson and Star attorney Denise Prescod argued that it is an unconstitutional violation of freedom of the press to impose prior restraint on truthful information obtained legally.

''The Jacksonville sheriff's office made the information public. By making it public, the press has the right to print it,'' Ms. Prescod said.

In testimony, Simpson said the newspaper violated its own policy and published the woman's name by mistake.

The newspaper did not settle out of court because it was within its rights to publish the name and because its non-publication policy is voluntary, Simpson said.

''If we had settled out of court, we have been condoning and admitting that we thought the law was valid and we don't think the law is valid,'' he said.

Tom Julin, a media attorney, said there have been two other recent cases under the statute, and both were overturned on appeal because the information was public at the time it was published.

In those cases, reporters identified or broadcast pictures of rape victims who appeared in public trials. This case is different, he said, because the woman was identified when the rape was reported rather than in the course of a trial. No arrest was made in the case.