All nine leaders face charges related to public nuisance. They said the hearing was largely procedural and didn't require them to enter pleas.
Nine leaders of Hong Kong's Umbrella Movement which spearheaded the 2014 democracy protests appeared in court on Thursday after their surprise summons.
All nine leaders were charged with starting a mass protest which has seen the main streets of Hong Kong occupied by sit in protesters carrying yellow umbrellas.
The protest paralysed parts of the city for months.
The nine were charged on Monday, just a day after a new Beijing-backed leader, Carrie Lam, was chosen as the city's next leader.
Lam's apppointment is seen by critics of China's attitude to its territory as a worrying sign after she vowed to heal divisions in the Chinese-ruled city and unite society.
The protest leaders entered the magistrates' court smiling and shaking hands with a few dozen supporters, some holding yellow umbrellas - a symbol of the 2014 civil disobedience movement.
TRT World's Pamela Ambler reports from Hong Kong.
The leaders face charges including conspiracy to commit public nuisance and inciting others to do the same.
Six others, including two legislators and two former student protest leaders, were also charged with crimes related to public nuisance.
The nine told the court they understood the charges, but the hearing was largely procedural and didn't require them to enter pleas.
Outside the court, about a dozen pro-China protesters jeered at the protest leaders, cursing them in colourful Cantonese while slapping photos of them with flip-flops.