In a report released Wednesday, the human rights organization said Turkish authorities denied citizens the right to peacefully assemble and protest a government plan to create a replica of Ottoman military barracks in the place of Gezi Park in Istanbul.
Some 8,000 people were injured and three died in the July protests.
"The attempt to smash the Gezi Park protest movement involved a string of human rights violations on a huge scale. They include the wholesale denial of the right to peaceful assembly and violations of the rights to life, liberty and the freedom from torture and ill-treatment," said Andrew Gardner, Amnesty International's expert on Turkey.
The report said protesters were beaten, resulting in at least one death; police fired plastic bullets at protesters' heads; tear gas canisters were fired at protesters and in homes, resulting in injuries and at least one death; chemical irritants were added to water cannon tanks; women protesters were sexually abused by law enforcement, and police used live ammunition, killing one person.
"The levels of violence used by police in the course of Gezi Park protests clearly show what happens when poorly trained, poorly supervised police officers are instructed to use force -- and encouraged to use it unsparingly -- safe in the knowledge that they are unlikely ever to be identified or prosecuted for their abuses," Gardner said.