Four ships of the United States Navy have been named USS Illinois in honor of the 21st state.

• The first USS Illinois (sloop) , a screw sloop-of war, was laid down but never completed.
• The second USS Illinois (BB-7), lead ship of her class of battleship, served for over half a century and was eventually renamed Prairie State.
• The third USS Illinois was a diesel-powered trawler acquired by the Navy, renamed USS Albatross (AM-71) , and employed as a minesweeper.
• The fourth USS Illinois (BB-65), would have been a Iowa-class battleship, if her construction had not been cancelled before she was launched.