The Chief Master Sergeant of the Air Force (acronym: CMSAF) is a unique non-commissioned rank in the United States Air Force. The holder of this rank and position of office represents the highest enlisted level of leadership in the Air Force, unless an enlisted airman is serving as the Senior Enlisted Advisor to the Chairman. The CMSAF provides direction for the enlisted corps and represents their interests, as appropriate, to the American public, and to those in all levels of government. The CMSAF is appointed by the Air Force Chief of Staff (AF/CC) and serves as the senior enlisted advisor to the Air Force Chief of Staff and the Secretary of the Air Force on all issues regarding the welfare, readiness, morale, and proper utilization and progress of the enlisted force.

The current Chief Master Sergeant of the Air Force is Chief JoAnne S. Bass (/bæs/). On August 14, 2020, Chief Bass succeeded Chief Kaleth O. Wright, to become the 19th Chief Master Sergeant of the Air Force.

Although the Chief Master Sergeant of the Air Force is a non-commissioned officer, protocol states that the CMSAF has precedence over all lieutenant generals at joint events, and over all lieutenant generals except the Air Force Director of Staff at Air Force exclusive events.