Senior Airman (SrA) is the fourth enlisted rank and highest non-NCO enlisted rank in the UNSC Air Force, immediately below Staff Sergeant, and above Airman First Class. The pay grade for Airman is E-4. It is equal to both Specialist and Corporal in the Army, Corporal in the Marine Corps, and Petty Officer Third Class in the Navy.

The Air Force promotes an Airman First Class (A1C) to Senior Airman upon a commander's recommendation after 36 months time in service and 20 months time in the grade of A1C, or 28 months time in A1C, whichever comes first. Outstanding Airmen First Class, limited to no more than 15 percent of the total, may be promoted to Senior Airmen six months early, in a competitive process which normally involves going before a competitive board. Senior Airmen are expected to be technically proficient and begin to develop leadership skills.