Henry Gassaway Davis (16 November 1823 - March 11, 1916) was a U.S. Democratic politician from West Virginia. Born near Woodstock, Maryland , Davis worked on a farm until 1843, when he began to work for the Baltimore and Ohio Railroad as a brakeman and conductor. Later he was put in charge of the Piedmont, Virginia terminal of the railroad, and soon went into coal mining and banking in Piedmont. In 1865 he was elected a member of the West Virginia state house of delegates in 1866, Piedmont having become a part of the new state, and became a state senator in 1869. In 1871, he was elected to the United States Senate, serving two terms, with his service ending in 1883.

Following his service in the Senate, Davis retired to Elkins, West Virginia, where he resumed banking and coal mining. Davis represented the U.S. at the Pan-American Conferences of 1889 and 1901, and in 1904, Davis became the Democratic nominee for Vice President on a ticket with Alton B. Parker that went down to defeat at the hands of Theodore Roosevelt's Republicans. At age 81, he was the oldest person to be nominated for President or Vice President on a major party ticket.

Davis in his last years acted as chairman of the permanent Pan American Railway Committee (1901-1916), and died in Washington, DC.