HONG KONG — Joshua Wong, the Hong Kong pro-democracy protest leader who became a symbol of the 2014 Umbrella Movement, will return to prison after an appeals court ruling Thursday.

Mr. Wong, 22, was one of the most prominent faces of the Umbrella Movement. A skinny teenager with glasses and a bowl cut, he urged on protesters who blocked several major roads for nearly three months in a call for freer elections.

He was sentenced to three months in prison last year over his actions during the court-ordered dismantling of a protest camp in the crowded Mong Kok district in November 2014. After being held six days, he was released on bail pending his appeal.

Mr. Wong had sought to have his sentence overturned. The court on Thursday instead reduced his term to two months because of his age at the time of his 2014 arrest.