The Battle of Hampton Roads, also referred to as the Battle of the Monitor and Merrimack (rebuilt and renamed as the CSS Virginia) or the Battle of Ironclads, was a naval battle during the American Civil War.

It was fought over two days, March 8–9, 1862, in Hampton Roads, a roadstead in Virginia where the Elizabeth and Nansemond rivers meet the James River just before it enters Chesapeake Bay adjacent to the city of Norfolk. The battle was a part of the effort of the Confederacy to break the Union blockade, which had cut off Virginia's largest cities and major industrial centers, Norfolk and Richmond, from international trade.^{[38 ]}At least one historian has argued that the Confederacy, rather than trying to break the blockade, was simply trying to take complete control of Hampton Roads in order to protect Norfolk and Richmond.^[39]

This battle has major significance because it was the first meeting in combat of ironclad warships, USS Monitor and CSS Virginia. The Confederate fleet consisted of the ironclad ram Virginia (built from the remnants of the burned steam frigate USS Merrimack, newest warship for the United States Navy / Union Navy) and several supporting vessels. On the first day of battle, they were opposed by several conventional, wooden-hulled ships of the Union Navy.

The battle received worldwide attention, and it had immediate effects on navies around the world. The preeminent naval powers, Great Britain and France, halted further construction of wooden-hulled ships, and others followed suit. Although Britain and France had been engaged in an iron-clad arms race since the 1830s, the Battle of Hampton Roads signaled a new age of naval warfare had arrived for the whole world.^[40] A new type of warship, monitor, was produced on the principle of the original. The use of a small number of very heavy guns, mounted so that they could fire in all directions, was first demonstrated by Monitor but soon became standard in warships of all types. Shipbuilders also incorporated rams into the designs of warship hulls for the rest of the century.^[41]