|Died||April 19, 1896 (aged 62–63)|
|Place of burial||Marion National Cemetery, Marion, Indiana|
|Service/branch||United States Navy|
|Battles/wars||American Civil War
• Battle of Mobile Bay
|Awards||Medal of Honor|
Nicholas Irwin (1833 – April 19, 1896) was a Union Navy sailor in the American Civil War and a recipient of the U.S. military's highest decoration, the Medal of Honor, for his actions at the Battle of Mobile Bay.
Born in 1833 in Denmark, Irwin immigrated to the United States and was living in New York when he joined the U.S. Navy. He served during the Civil War as a seaman on the USS Brooklyn. At the Battle of Mobile Bay on August 5, 1864, he "fought his gun with skill and courage" despite heavy fire. For this action, he was awarded the Medal of Honor four months later, on December 31, 1864.
Irwin's official Medal of Honor citation reads:
On board the U.S.S. Brooklyn during action against rebel forts and gunboats and with the ram Tennessee, in Mobile Bay, 5 August 1864. Despite severe damage to his ship and the loss of several men on board as enemy fire raked her decks from stem to stern, Irwin fought his gun with skill and courage throughout the furious battle which resulted in the surrender of the prize rebel ram Tennessee and in the damaging and destruction of batteries at Fort Morgan.
- "Nicholas Irwin". Hall of Valor. Military Times. Retrieved October 9, 2012.
- "Civil War Medal of Honor Recipients (A–L)". Medal of Honor Citations. United States Army Center of Military History. June 26, 2011. Retrieved October 9, 2012.
- "Marion National Cemetery". United States Department of Veterans Affairs. January 6, 2011. Retrieved October 9, 2012.