BEIJING — An outspoken Chinese human rights lawyer was sentenced to four and a half years in prison on Monday, the last to be prosecuted among hundreds of legal activists who had been rounded up in a crackdown in 2015.

The lawyer, Wang Quanzhang, was found guilty of “subversion of state power,” the No. 2 Intermediate People’s Court of Tianjin said on its website. That charge is usually applied to critics of the ruling Communist Party who are accused of organizing political challenges.

Other lawyers and activists who had been picked up in an expansive campaign by the government that began in the summer of 2015 were either released or put on trial and sentenced. But Mr. Wang, 42, had been held for nearly three and a half years before he faced charges in a closed trial in Tianjin on Dec. 26 that even his wife was barred from attending.

The crackdown, which included televised show trials in which lawyers confessed to plotting to overthrow the government and working on behalf of foreign forces, is a part of President Xi Jinping’s efforts to obliterate threats to the party’s control.