1961 in the Vietnam War

January
John Fitzgerald Kennedy is inaugurated as the 35th U.S. President and declares, "...we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, to insure the survival and the success of liberty." Privately, outgoing President Eisenhower tells him "I think you're going to have to send troops..." to Southeast Asia.
 * January 20, 1961

February
The communist military force People's Liberation Armed Forces (PLAF) is formed under the leadership of Tran Luong.

May
Vice President Lyndon B. Johnson visits President Diem in South Vietnam and hails the embattled leader as the "Winston Churchill of Asia."

October
As part of Farm Gate John F. Kennedy authorized the deployment of a detachment of Air Commandos to South Vietnam.

December
The first American dies in a battlefield engagement. Cryptologist James T Davis was out on patrol on December 22, 1961 when ambushed. He and the group of South Vietnamese he was with were killed while fighting the Viet Cong communist insurgency.
 * December 22