Prince Karl Anton of Hohenzollern-Sigmaringen (German: Karl Anton Friedrich Wilhelm Ludwig Prinz von Hohenzollern-Sigmaringen; 1 September 1868 – 21 February 1919) was a member of the Princely House of Hohenzollern-Sigmaringen.

Karl Anton was the third and youngest son of Leopold, Prince of Hohenzollern and Infanta Antónia of Portugal.

Karl Anton's elder brothers were William, Prince of Hohenzollern and Ferdinand I of Romania.

On 28 May 1894 in Brussels, Karl Anton married his cousin Princess Joséphine Caroline of Belgium (Brussels 18 October 1872 - Namur 6 January 1958), daughter of Prince Philippe, Count of Flanders and his wife Princess Marie of Hohenzollern-Sigmaringen.

Karl Anton served as a Prussian Lieutenant general during World War I and died after his return to Namedy in 1919, at age 50.