Princess Hassa bint Salman has received a 10-month suspended sentence and a 10,000 euro (£8,900) fine after she told her bodyguard to beat up the man for taking photos inside her home.
The plumber, Ashraf Eid, said the guard tied him up and forced him to kiss the princess’ feet.
Princess Hassa was found guilty of complicity to violence with a weapon and complicity to kidnap.
She has consistently denied the allegations and was not present for the Paris court’s verdict and sentencing, despite French authorities issuing an international arrest warrant.
The penalties were significantly tougher than the six-month suspended sentence and 5,000 euro fine prosecutors had sought against Princess Hassa.
Her lawyer, Emmanuel Moyne, called the verdict "inexplicable" and said he would appeal.
Mr Eid told police that the bodyguard tied him up at the princess’ request after he photographed a room so he could return furniture to its original layout once he finished his work.
"The princess noticed that her face was reflected in the bathroom and that she had been filmed,” he said.
“She called me a dog and called her bodyguard saying in Arabic, 'This one, take his phone. He filmed me.’”
At one point, the princess allegedly said: “Kill him, the dog, he doesn't deserve to live."
It is a crime in Saudi Arabia to film a princess without permission.
Princess Hassa’s bodyguard, Rani Saida, told the court in July that he heard her cry for help and rushed to help.
He was found guilty on charges of violence, sequestration and theft.
Unlike his employer, Saida was in court for the verdict and his sentence - an eight-month suspended jail term and a 5,000 euro fine - matched what the prosecution requested.
His lawyer said he would decide on an appeal in the coming days.
Agencies contributed to this report