Wang Mo was convicted of "inciting subversion of state power" by the Guangzhou Intermediate People's Court, his lawyer Chen Keyun told AFP.
He was among five people sentenced by Chinese courts for the offence on Friday, according to lawyers and activists.
In 2014 mass rallies brought parts of the semi-autonomous Chinese city of Hong Kong to a standstill for 79 days as residents called for fully free elections for future leaders, but failed to win any concessions from the Hong Kong or Chinese governments.
Under President Xi, China's ruling Communist Party has tightened controls over civil society, detaining or interrogating more than 200 human rights lawyers and activists in what analysts have called one of the biggest crackdowns on dissent in years. Three other activists were sentenced to jail terms, ranging from one to four years, for inciting subversion in other ways, lawyers told AFP.
Liang Qinhui was jailed for 18 months according to his lawyer Wu Kuiming. Another of his attorneys previously told Radio Free Asia that Liang had posted images and messages critical of the Chinese leadership and political system online, adding: "I don't think his actions amount to criminal behaviour".
Huang Jingyi was sentenced to two years by the same court, Liu added.
