William Charles Kueffner (February 27, 1840 – March 18, 1893) was an officer in the Union Army during the American Civil War who served in the 9th Illinois Infantry in the Western Theater in several campaigns.

He was later brevetted as a brigadier general for bravery in combat and was a noted attorney in southern Illinois following the war.

Following his final battle wound, he was transferred to the 23rd Veterans Reserve Corps, with whom he served in non-combat areas.

Volunteers in the omnibus promotions following the war, backdated to March 13, 1865, for "gallant and meritorious services".

After the war, Kueffner was the collector of internal revenue for the 12th district of Illinois until removed in 1869 by order of President Ulysses S. Grant for political reasons.