La Follette was born in Madison, Wisconsin, a member of the politically prominent La Follette family. He was the son of Wisconsin Congressman, Governor, and U.S. Senator Robert M. "Fighting Bob" La Follette, Sr., and Belle Case La Follette, brother of U.S. Senator Robert M. La Follette, Jr., brother of Fola La Follette, whose husband was the playwright George Middleton, and uncle of Wisconsin Attorney General Bronson La Follette.

La Follette served as a second lieutenant in the United States Army Infantry in 1918, during World War I. In 1919 he received a Bachelor of Arts degree from University of Wisconsin and in 1922 a Bachelor of Laws degree. He married Isabel Bacon (1898–1973) in 1923. They had three children: son Robert (c. 1927), and daughters Judith (c. 1929) and Sherry (1936).

He was the district attorney for Dane County, Wisconsin, from 1925 to 1927. La Follette was Governor of Wisconsin from 1931 to 1933 and 1935 to 1939. He was first elected as a progressive member of the Republican Party in the 1930 election.

After a defeat in the 1932 Republican Primary, however, La Follette, along with his brother, Robert M. La Follette, Jr., created the Wisconsin Progressive Party and both ran successfully under its ticket in 1934. The gregarious governor was known as "Phil" on the streets of Madison during his governorship, much as his father had been known as simply "Bob". His governorship saw the implementation of many of the progressive measures of the New Deal, with La Follette being responsible for the implementation of some of them on the state level before the Roosevelt Administration could do so on the national level.

La Follette was defeated seeking reelection as governor in 1938. That spring he had attempted to launch the National Progressive Party of America in an attempt to create a national third party (as the La Follettes had helped create in Wisconsin). This party was named the National Progressives of America upon its formation. The goals of the party were to lead a realignment of American politics along more concrete liberal and conservative lines. Despite his efforts, the NPA was unsuccessful and La Follette never held public office after 1939.

Much as his father opposed U.S. entry into World War I, Phil La Follette strongly opposed, like most other Americans, U.S. entry into World War II. Once war was declared, he abandoned his opposition and joined the U.S. Army, serving on the staff of General Douglas MacArthur. He would later spearhead a slate of delegates to the 1948 Republican National Convention supporting MacArthur's nomination for the presidency. Such a slate included many people La Follette had opposed during the Great Depression, but turned to out of a common interest to support MacArthur, a fact which perplexed many of his contemporaries.

From 1955 to 1959, La Follette served as president of Hazeltine Electronics, and made his home in Douglaston, New York. He later returned to Wisconsin, wrote his autobiography, and was active in the State Historical Society of Wisconsin.

He died in Madison, Wisconsin.^[1]

• La Follette, Philip Fox, Adventure in politics: the memoirs of Philip La Follette edited by Donald Young, New York: Holt, Rinehart and Winston, 1970.

• Kasparek, Jonathan. Fighting Son: A Biography of Philip F. La Follette. Madison: Wisconsin Historical Society, 2006. ISBN 0-87020-353-3.

• La Follette Family Papers in the Library of Congress
• Philip F. La Follette, Dictionary of Wisconsin History, Wisconsin State Historical Society