What is the O-1 rank in the Marine Corps?

The O-1 rank in the Marine Corps is the Second Lieutenant. This rank is the entry-level officer rank in the Marine Corps and is typically held by officers who have recently completed their training and are in the initial stages of their career. Second Lieutenants are usually tasked with various responsibilities, including leading small units and serving as platoon leaders.

The significance of the O-1 rank is that it represents the first step into commissioned officer leadership within the Marine Corps, where individuals begin to develop their leadership skills and knowledge about military operations. Second Lieutenants often serve under more experienced officers, gaining valuable insights and experience that will benefit their future service. Understanding the structure and order of ranks is crucial for proper respect and protocol within the military hierarchy.