Collin Thomas was born on May 2, 1977, in San Diego, California. He enlisted in the U.S. Navy on February 20, 1997, and completed basic training at NTC Great Lakes, Illinois, in April 1997. After completing Hospital Corpsman training, Petty Officer Thomas attended Basic Underwater Demolition/SEAL training at NAB Coronado, California, from April to October 1998, followed by Jump School at Fort Benning, Georgia, and SEAL Qualification Training. He then attended Special Operations Combat Medic training before serving with SEAL Team FOUR at NAB Little Creek, Virginia, from February 2000 to December 2004. His next assignment was with SEAL Team TWO at NAB Little Creek from December 2004 to May 2006, followed by service with Naval Special Warfare Development Group (DEVGRU) at Dam Neck Annex, Virginia, from June 2006 until he was killed in action in Afghanistan on August 18, 2010. During the War on Terrorism he deployed to Trans Sahara Africa in support of Operation Enduring Freedom in 2005 and 2006, to Iraq in support of Operation Iraqi Freedom in 2007, and to Afghanistan in Support of Operation Enduring Freedom multiple times. Chief Petty Officer Thomas was buried at Forest Lawn Memorial Gardens in Morehead, Kentucky.

His Silver Star Citation reads:

For conspicuous gallantry and intrepidity in action against the enemy while serving as an Assistant Team Leader while assigned to a Joint Task Force in support of Operation ENDURING FREEDOM on 18 August 2010. Chief Petty Officer Thomas and his team were conducting a sensitive sift exploitation associated with known armed enemy fighters in the area of operation. Immediately after insertion, the assault force received effective fire from a tree line directly to their East. The force bounded toward the enemy and took multiple casualties on their Northern most flank. Realizing the entrenched enemy had a superior fighting position; Chief Petty Officer Thomas broke cover and led his team on a flanking maneuver to support the Northern element who was engaged in heavy contact. As his team maneuvered, he observed an armed enemy fighter inside a six-foot deep trench that ran the length of the tree line. Chief Petty Officer Thomas, identifying the threat that the enemy posed on the rest of his team, boldly charged and engaged the enemy while being fired upon by an automatic weapon. He eliminated the enemy, but was mortally wounded during the exchange of gunfire. Chief Petty Officer Thomas' actions directly saved the lives of his teammates. By his bold leadership, courageous actions, and total devotion to duty, Chief Petty Officer Thomas reflected great credit upon himself and upheld the highest traditions of the United States Naval Service.