John Ralph McDowell was a Republican member of the United States. House of Representatives from Pennsylvania.
McDowell was born in Pitcairn, Pennsylvania.
He graduated from Randolph-Macon Military Academy in Front Royal, Virginia, in 1923.
He was employed as a reporter on the Pitcairn Express in 1923 and worked on various newspapers until 1929. He was magistrate of Pitcairn from 1925 to 1928. He became editor of the Wilkinsburg Gazette in 1929 and president of the Wilkinsburg Gazette Publishing Company in 1933.
McDowell was elected as a Republican to the Seventy-sixth Congress, but was an unsuccessful candidate for reelection in 1940 and 1942.
He was again elected in 1946 to the Eightieth Congress. He was an unsuccessful candidate for reelection in 1948.