During the riots – the worst ethnic violence seen in China in decades - members of Xinjiang's native Muslim Uighur community attacked ethnic Han Chinese residents in the regional capital, Urumqi.
The clashes broke out following street protests against attacks on Uighur workers at a toy factory in southern China in June that left two Uighurs dead.
The sentences come three days after a court in southern China sentenced a man to death for his role in the toy factory brawl.
China's government has blamed the riots on overseas Uigur groups which it says are terrorists agitating for greater Uighur rights in their Xinjiang homeland.
According to the government, most of the 197 killed in the Urumqi riots were Han Chinese.
The ethnicity of those convicted on Monday was not reported, although all appeared to have Uighur names.
Chinese state television showed tight security and deserted streets outside the Urumqi court on Monday as the convictions were read out.
Urumqi has been under extremely heavy security since the July riots, with armed police manning road blocks and patrolling the streets.
According to earlier reports police have detained more than 700 people suspected of crimes related to the riots, although how many will face prosecution remains unclear.