The 57-year-old was travelling to the set of his new TV show Catch 22 in Costa Corallina when a vehicle turned and struck him.
Private media firm Mediaset, citing gossip magazine Chi, said the accident occurred near Costa Corallina, in the province of Olbia.
A picture from La Nuova suggests that Clooney hit a auto while on the motorway.
A picture from La Nuova shows a smashed windscreen, which suggests George hit it during the crash, but despite this, his condition is not thought to be serious.
A fire extinguisher can be seen on the road but no people from the accident were involved.
Sardinian hospital John Paul II says Clooney has already been discharged, according to NBC News.
They claim that he injured his pelvis in the smash, but after being x-rayed was sent home. La Nuova also reports that George's wife, Amal Clooney, rushed to be by his side when she heard news of his hospitalization.
Clooney is now filming TV drama Catch-22 on the Italian island.
George has been working hard in the region for his new project Catch 22, with the star directing, producing and starring in the six episode miniseries based on Joseph Heller's seminal novel.
Calls and emails to Clooney's spokesman in regards to the accident weren't immediately returned, according to Associated Press.