What is the rank associated with the O-3 level in the U.S. Navy?

The rank associated with the O-3 level in the U.S. Navy is Lieutenant. In the Navy's rank structure, the O-3 designation is specifically assigned to the rank of Lieutenant, which falls under the category of commissioned officers. This rank follows the O-2 level, which is the rank of Lieutenant Junior Grade, and precedes the O-4 level, which is the rank of Lieutenant Commander.

Understanding this hierarchy is essential for grasping the structure and progression of ranks within the U.S. Navy, as it delineates each officer's responsibilities and authority. The other ranks listed, such as Commander and Captain, correspond to higher levels within the officer ranks—the O-5 and O-6 levels, respectively—while Lieutenant Commander is an O-4 rank, situated just above Lieutenant. This clear distinction within the ranks helps maintain the organizational structure vital for military operation and leadership.