After the end of the war, Sebille left active duty with the Air Force and began work as a commercial airline pilot. However he returned to the Air Force in July 1946 after he was offered a commission as a First Lieutenant. He held several positions, first as a staff officer with the Ninth United States Air Force headquarters at Biggs Army Airfield at Fort Bliss, Texas. Shortly thereafter, Sebille was assigned as an P-51 Mustang and P-80 Shooting Star instructor pilot, teaching other pilots how to transition from conventional fighter aircraft to newer jet engine powered models. Sebille then attended Air Tactical School at Tyndall Field, Florida. He was then assigned to Clark Air Base in the Philippines in 1948. During this time, he flew an P-51D named "Nancy III" (tail number 44-74112). In November 1948, Sebille was once again promoted to major and made the commanding officer of the 67th Fighter-Bomber Squadron, 18th Fighter-Bomber Wing, a component of the Fifth United States Air Force stationed in Japan for post-World War II occupation duties. In November 1949, the squadron began receiving new P-80's but continued to fly a mix of P-80 and P-51 aircraft. Eventually, the squadron transitioned entirely to P-80s, then back to P-51s. During this time, Sebille was known to spend time in his squadron's Quonset hut. He frequently discussed fighting and death, including sentiments supporting suicide attack, at one point saying "If you have to die, then take some of the enemy with you." During this time Sebille worked mostly administrative duty as the squadron absorbed new aircraft and pilots in Japan.