Percy Carl Klaehn (1896 – May 8, 1984) was an educator and politician in Saskatchewan, Canada. He served as mayor of Saskatoon in 1964.
He was born in Valleyfield, Quebec and came west with his family while still young. Klaehn served with Princess Patricia's Canadian Light Infantry during World War I and was wounded at the Battle of Vimy Ridge. At the start of World War II, Klaehn joined the Saskatoon Light Infantry. He was named commander of The Cameron Highlanders of Ottawa and took part in the Invasion of Normandy in June 1944. He later commanded the 8th Canadian Infantry Brigade in Belgium. He then went to England as commander of the Canadian School of Infantry. In the fall of 1945, Klaehn returned to Saskatoon as regional administrator for the federal Department of Veterans Affairs. In 1946, he became commander of the 17th Infantry Brigade and later the 21st Militia of Saskatoon. Klaehn retired from the militia in 1958 but was named honorary lieutenant-colonel for the North Saskatchewan Regiment.
Between the First and Second World Wars, Klaehn also taught school in Saskatoon, North Battleford and Weyburn. He was a high school coach for Ethel Catherwood, who later won a gold medal for Canada in the high jump at the 1928 Summer Olympics.