The general courts-martial will begin next month, said Master Gunnery Sgt. John Cordero of the U.S. Marine Corps Air Station in Iwakuni in southern Japan.
The four Marines - accused of an attack on a 19-year-old woman in October - were charged by the military in December.
Japanese authorities investigated the incident but local prosecutors dropped the case in November. Officials refused to provide reasons for not pursuing prosecution.
Lans Cpl. Larry A. Dean, 20, will face the court in April and Sgt. Lanaeus J. Braswell, 25, in May, Cordero said.
Dates for two other Marines - Gunnery Sgt. Carl M. Anderson, 39, and Gunnery Sgt. Jarvis D. Raynor, 34, have not been set yet, he said, adding that the military is not releasing their hometowns.
The decision to court-martial them was made Monday after two days last month of preliminary hearings, the military equivalent of civilian grand jury proceedings, according to Cordero.
The move came as anger has risen on the southern island of Okinawa over the arrest in February of another serviceman on suspicion of raping a 14-year-old girl. Japanese authorities have dropped that case, but the U.S. military is still investigating.
In the Iwakuni case, media reports say the woman met the servicemen at a restaurant in Hiroshima, and the men drove her to a nearby parking lot where they allegedly raped and robbed her.
Authorities were not releasing details, but Kyodo reported that the woman said she had agreed to have sex with one of the men, but then the three others joined in, with all four of them raping her.
About 50,000 U.S. troops are based in Japan under a security pact between the two countries. Many Japanese complain of crime, pollution and noise associated with the bases.
In the Okinawa case, Japanese police arrested Staff Sgt. Tyrone Luther Hadnott, 38, from Camp Courtney in Okinawa over the alleged attack in February.
Hadnott was released later after the girl withdrew her criminal complaint against him and U.S. military authorities were investigating him.