Lieutenant is a rank, used in many military, paramilitary, and civilian contexts:
- In many military organizations, including the United States Army and Air Force, lieutenant is a junior commissioned officer rank below a captain.
- In law enforcement and some federal agencies, a lieutenant is a superior rank, that can supervise one or several shifts.
- In organized crime, paramilitary, and terrorist organizations, lieutenant is an informal title given to the seconds and thirds-in-command.
- Tony Almeida – United States Marine Corps (Fox.com profiles)
- Peter Dennon – United States Air Force, drone pilot ("Day 9: 11:00am-12:00pm")
- Mark DeSalvo – United States Army, First lieutenant (Findings at CTU)
- Kintu – People's Freedom Army, lieutenant (24: Redemption)
- Kevin Newton – United States Army, First lieutenant and later Lieutenant Colonel (Findings at CTU)
- Southern – United States Navy, ranking officer aboard the Natalia ("Day 5: 4:00am-5:00am")
- Chris Tanner – United States Air Force, drone pilot ("Day 9: 11:00am-12:00pm")
- Ben Wilkins – Royal Air Force ("Day 9: 11:00am-12:00pm")