Thomas was born in Pennsylvania on October 6, 1958 and graduated from the United States Military Academy in 1980. Thomas was a member of the 75th Ranger Regiment. He led a Ranger Rifle platoon during the Invasion of Grenada in 1983, that was dropped from an MC-130 onto a landing strip in Grenada. He completed Infantry Officer Advanced Course in early 1986 and was assigned as Assistant S-3, Plans/Liaison Officer with 75th Ranger Regiment at Fort Benning, Georgia until 1987. Thomas was then assigned as a company commander with 3rd Ranger Battalion. In 1989, during the Invasion of Panama, he led his Ranger Rifle Company in another combat jump. In 1992, Thomas volunteered for and completed a specialized selection course for assignment to 1st Special Forces Operational Detachment-Delta, also known as Delta Force. He served as Operations Officer, Troop Commander, Executive Officer and Squadron Commander from 1992 to 1994 and 1996 to 1999. In June 1995 Thomas earned a master's degree from the Naval Command and Staff College in Newport, Rhode Island. From 2000 to 2002, he served as commanding officer of the 1st Ranger Battalion, 75th Ranger Regiment. Thomas crossed over from the special operations realm into the conventional warfare realm when he was selected by Lieutenant General Mark P. Hertling, then-commander of the 1st Armored Division, to be his deputy commander during the Iraq War, from 2007 to 2008. During that tour the division worked alongside Arabs and Kurds and despite the difficult relationship between the ethnic groups Thomas was praised by Hertling for "his ability to quickly fuse intelligence" adding, "He helped us fight better." After his tenure in the 1st Armored Division came to an end Thomas returned to special operations. From 2010 until 2012 Thomas served as the deputy commander of Joint Special Operations Command. As a major general, Thomas was in charge of all United States and NATO special forces in Afghanistan from 2012 until 2013. Every year between 2001 and 2013 Thomas deployed to Afghanistan as part of various special operations units. After commanding special forces units in Afghanistan, Thomas was promoted to lieutenant general and was reassigned to CIA headquarters in Langley, Virginia where he served as the Associate Director of the Central Intelligence Agency for Military Affairs. In August 2014, Thomas replaced Joseph Votel as the commander of Joint Special Operations Command. Votel was promoted to four-star general and replaced Admiral William H. McRaven as the commander of United States Special Operations Command. In a ceremony at MacDill Air Force Base, Florida, on March 30, 2016 Thomas took command of USSOCOM and received his fourth star. General Thomas retired from active duty on March 29, 2019.
