Denis (or Dennis) Buckley (c. 1844 – July 20, 1864) was a Canadian-born soldier who fought in the American Civil War.

Buckley received the country's highest award for bravery during combat, the Medal of Honor, for his action during the Battle of Peachtree Creek in Georgia on July 20, 1864.

He was honored with the award on April 7, 1865.

[4] Buckley was killed in action on July 20, 1864, at the Battle of Peachtree Creek, and his remains are interred at the Marietta National Cemetery in Marietta, Georgia.

[5] Capture of flag of 31st Mississippi (Confederate States of America).