Two detainees also were allegedly beaten and suffered minor abrasions but no broken bones or other injuries, Navy 5th Fleet spokeswoman Cmdr. Jane Campbell said.
The May 14 assaults occurred after a number of guards at Camp Bucca were attacked by the detainees, including spitting on the guards and throwing containers filled with human waste at them, Campbell said.
The case was the latest allegation of abuse against inmates in U.S. detention in Iraq, and it comes as the U.S. military has touted reforms of the prison system.
The issue drew international criticism in 2004 with the release of pictures of grinning U.S. soldiers posing with detainees at the Abu Ghraib facility west of Baghdad. Some were naked, being held on leashes or in painful and sexually humiliating positions.
That prison has since been closed, and 11 U.S. soldiers were convicted of breaking military laws. Five others were disciplined in the scandal.
The six sailors were charged with assault on detainees and will face courts-martial at Camp Bucca within the next 30 days, the Navy said.
Seven other sailors received nonjudicial punishment for failing to report the incidents, Campbell said. Two had their charges dismissed while others were reduced in rank or faced suspended punishment, she added, declining to be more specific.
The alleged assaults occurred at Camp Bucca, a detention center that houses 18,000 of the U.S. military's 21,000 inmates, in southern Iraq on May 14. A formal investigation began four days later.
"Two detainees suffered minor abrasions as a result of the alleged assaults," the statement said. "Eight others were confined overnight in a detainee housing unit which was sprayed with a riot control agent and then the ventilation secured."