The House Divided Speech was an address given by senatorial candidate and future president of the United States Abraham Lincoln, on June 16, 1858, at what was then the Illinois State Capitol in Springfield, after he had accepted the Illinois Republican Party's nomination as that state's US senator. The nomination of Lincoln was the final item of business at the convention, which then broke for dinner, meeting again at 8 pm. "The evening session was mainly devoted to speeches", but the only speaker was Lincoln, whose address closed the convention, save for resolutions of thanks to the city of Springfield and others. His address was immediately published in full by newspapers, as a pamphlet, and in the published proceedings of the convention. It was the launching point of his unsuccessful campaign for the senatorial seat held by Stephen A. Douglas; the campaign would climax with the Lincoln–Douglas debates. When Lincoln collected and published his debates with Douglas as part of his 1860 presidential campaign, he prefixed them with relevant prior speeches. The "House Divided" speech opens the volume.

Abraham Lincoln was an American lawyer, politician, and statesman, who served as the 16th president of the United States, from 1861 until his assassination in 1865. Lincoln led the United States through the American Civil War, defending the nation as a constitutional union, defeating the insurgent Confederacy, playing a major role in the abolition of slavery, expanding the power of the federal government, and modernizing the U.S. economy.