Kim Kardashian, the reality TV star and entrepreneur, is scheduled to testify on Tuesday in Paris court, where she will face the so-called “grandpa robbers” who are accused of violently stealing from her in the French capital nearly a decade ago.

Ms. Kardashian is expected to explain how she was gagged, bound with tape and zip ties, and robbed at gunpoint at a residence she rented during Paris Fashion Week in October 2016.

Ms. Kardashian, 44, has described in previous interviews the trauma she suffered when men dressed as police officers and wearing balaclavas burst into the property and stole valuables, including a $4 million diamond engagement ring.

But her appearance in court on Tuesday will mark the only time that she is expected to take the stand and face the men accused of robbing her.

From dawn, scores of journalists and curious onlookers hoping to catch a glimpse of Ms. Kardashian had lined up to get into the courtroom to sit in the public gallery. Under French law, cameras are not allowed in the court.

Theo Chbouki, an 18-year-old fashion student in the line, said that it was his first time attending a criminal trial and that he was curious to see Ms. Kardashian in a “serious” real-life setting, without the glossy veneer of social media or reality TV.