The 1898–99 United States Senate elections were elections in which the Republican Party gained eight seats in the United States Senate at the expense of the Democrats and several minor third parties. The Democrats saw strong gains in the concurrent 1898 House of Representatives elections. However, this group of Senators were last up for election in 1892, since which a major political realignment had occurred. Many state legislatures in northern states that had been controlled by Democrats during the third party system had flipped in the Republican wave years of 1894 and 1896, resulting in the huge number of seats the party gained in 1898.