David Ignatius Walsh (November 11, 1872 – June 11, 1947) was a United States politician from Massachusetts. As a member of the Democratic Party, he served in the state legislature and then as the 43rd Lieutenant Governor (1913–1914) and then as the 46th Governor (1914–1916). His first term in the U.S. Senate (1919–1925) was followed by a brief hiatus from government, after which he was elected to the U.S. Senate four times, serving from 1926 to 1947.