- Lieutenant Colonel Frank A. Barker – commander of the Task Force BARKER, a battalion-sized unit, assembled to attack the 48th Battalion of the Viet Cong supposedly based in and around My Lai. He allegedly ordered the destruction of the village and supervised the artillery barrage and combat assault from his helicopter. Reported the operation as a success; was killed in Vietnam on June 13, 1968, in a mid-air collision before the investigation had begun.
- Captain Kenneth W. Boatman - an artillery forward observer; was accused by the Army of failure to report possible misconduct, but charge was dropped.
- Second Lieutenant Stephen Brooks – the 2nd Platoon Leader, Charlie Company; turned a body count of 60 for the second platoon; later killed himself in Vietnam.
- Major Charles C. Calhoun - operations officer of Task Force BARKER; charges against him of failure to report possible misconduct were dropped.
- Second Lieutenant William L. Calley Jr. – platoon leader, 1st Platoon, Charlie Company, First Battalion, 20th Infantry Regiment, 11th Infantry Brigade, 23rd Infantry Division. Was charged in deliberate murder of 102 civilians, found guilty and sentenced to life. Was paroled in September 1974 by the Secretary of the Army Howard Callaway.
- Lieutenant Colonel William D. Guinn Jr. - Deputy Province Senior Advisor/Senior Sector Advisor for Quangngai Province. Charges against him of dereliction of duty and false swearing brought by the Army were dropped.
- Colonel Oran K. Henderson – 11th Infantry Brigade commander, who ordered the attack and flew in a helicopter over Mỹ Lai during it. After Hugh Thompson immediately reported multiple killings of civilians, Henderson started the cover-up by dismissing allegation about the massacre and reporting to the superiors that indeed 20 people from My Lai died by accident. Was accused of alleged cover-up and false swearing by the Army; charges were dropped.
- Major General Samuel W. Koster – commander of the 23rd Infantry Division (United States) of the United States Army, known as AMERICAL Division, was not involved with the planning of the My Lai search-and-destroy mission. However, during the operation he flew over My Lai and monitored the radio communications. Afterward, Koster did not followed up with the 11th Brigade commander colonel Henderson on the initial investigation, and later was caught into cover-up. Was charged by the Army with failure to obey lawful regulations, dereliction of duty, and alleged cover-up; charges dropped. Later was demoted to Brigadier General and stripped of a Distinguished Service medal.
- Captain Eugene M. Kotouc – military intelligence officer assigned to Task Force BARKER; he partially provided information, on which the Mỹ Lai combat assault was approved; together with Medina and a South Vietnamese officer, he interrogated, tortured and allegedly executed VC and NVA suspects later that day. Was charged with maiming and assault, tried by the jury and acquitted.
- Captain Dennis H. Johnson - 52d Military Intelligence Detachment, assigned to Task Force BARKER, was accused of failure to obey lawful regulations, however charges were later dropped.
- Second Lieutenant Jeffrey U. Lacross - platoon leader, 3rd Platoon, Charlie Company; testified that his platoon did not meet any armed resistance in My Lai, and that his men did not kill anybody, however, since, in his words, both Calley and Brooks reported a body count of 60 for their platoons, he then submitted a body count of 6.
- Major Robert W. McKnight - operations officer of the 11th Brigade; was accused of false swearing by the Army, but charges were subsequently dropped.
- Captain Ernest L. Medina – commander of Company C, First' battalion, 20th Infantry; nicknamed Mad Dog by subordinates. He planned, ordered, and supervised the execution of the operation in Son My village. Was accused of failure to report a felony and of murder; went to trial and was acquitted.
- Captain Earl Michaels - company commander during My Lai operation; he died in a helicopter crash three months later.
- Brigadier General George H. Young Jr. - assistant division commander, 23rd Infantry Division; charged with alleged cover-up, failure to obey lawful regulations and dereliction of duty by the Army; charges were dismissed.
- Major Frederic W. Watke - commander of Company B, 123rd Aviation Battalion, 23rd Infantry Division, providing helicopter support on March 16, 1968. Testified that he informed Colonel Henderson about killings of civilians in My Lai as reported by helicopter pilots. He was accused of failure to obey lawful regulations and dereliction of duty; charges were dropped.
- Captain Thomas K. Willingham - Company B, Fourth Battalion, Third Infantry Division, assigned to Task Force BARKER; charged with making false official statements and failure to report a felony; charges were dropped.