Connally served in the United States Navy during World War II, first as an assistant to James V. Forrestal. Then, he served again as part of the planning staff for the invasion of North Africa by General Dwight D. Eisenhower. He transferred to the South Pacific Theater, where he served with distinction. He was a fighter-plane director aboard the aircraft carrier USS "Essex" and won a Bronze Star for bravery. He was shifted to another Essex class aircraft carrier which was the USS "Bennington". He won a Legion of Merit. He was also involved in the military campaigns in the Gilbert, Marshall, Ryukyu, and Philippine islands. He quit the military in 1946 at the rank of lieutenant commander.