Dennis Tellier was born in 1950 in Woonsocket, Rhode Island. He enlisted in the U.S. Marine Corps on March 29, 1968, and completed basic training at MCRD Parris Island, South Carolina, in June 1968. Pvt Tellier next attended infantry training at MCB Camp Lejeune, North Carolina, from June to July 1968, followed by Combat Engineer training at NAS Lakehurst, New Jersey, and at Camp Lejeune, from July to October 1968. His first assignment was as a combat engineer with Company D, 11th Engineer Battalion of the 3rd Marine Division in South Vietnam from December 1968 until he was captured and taken as a Prisoner of War on June 19, 1969. After spending 1,378 days in captivity, Sgt Tellier was released during Operation Homecoming on March 27, 1973. He was briefly hospitalized at the Marine Barracks, Naval Base Brooklyn, New York, and then received an honorable discharge from the Marine Corps on October 25, 1973.

His Navy Commendation Medal w/Valor Citation reads:

For meritorious service while interned as a Prisoner of War in Southeast Asia from June 1969 to March 1973. Soon after his capture, Sergeant Tellier escaped from his captors and evaded their efforts to recapture him for a period of several hours. Once reimprisoned and in spite of the harshness and hostile environment, he conducted himself in an exemplary manner. His outstanding performance and courage clearly demonstrated his devotion to the United States. By his dedication to duty, Sergeant Tellier reflected credit upon himself, the Marine Corps, and the United States Naval Service.

The Combat Distinguishing Device is authorized.