Henry Highland Garnet (December 23, 1815 – February 13, 1882) was an American abolitionist, minister, educator, orator, and diplomat. Having escaped as a child from slavery in Maryland with his family, he grew up in New York City. He was educated at the African Free School, and later the Noyes Academy and the Oneida Institute. As a Presbyterian minister, his drive for abolitionism was based in religion.

Garnet was a prominent member of the movement that favored political action over moral suasion. Renowned for his skills as a public speaker, he urged enslaved African Americans to take direct action in freeing themselves from slavery. Garnet was a supporter of the emigration of American free blacks to Mexico, Liberia, or the West Indies, founding the African Civilization Society alongside Martin Delany.

He was a member of Prince Hall Freemasonry, an African American fraternal organization that provided sick and death benefits for members as well as fought for abolition and civil rights.

In 1841, Garnet married abolitionist Julia Ward Williams and they had three children. Stella (Mary Jane) Weems, a runaway slave from Maryland, lived with the Garnets. She was likely adopted by them and employed as their governess. When Henry preached against slavery, he brought her up to talk about her own experiences and about her family still enslaved in Maryland.

In 1852, Garnet became a missionary with the United Presbyterian Church of Scotland. He traveled to Jamaica with his family until 1855, when he returned to the United States due to health concerns.

On Sunday, February 12, 1865, he delivered a sermon in the U.S. House of Representatives while it was not in session, becoming the first African American to speak in that chamber. His sermon was given on the occasion of Congress' passage of the Thirteenth Amendment, and the end of slavery.

Henry Garnet was born into slavery in Chesterville (then New Market), Kent County, Maryland, on December 23, 1815. "[H]is grandfather was an African chief and warrior, and in a tribal fight he was captured and sold to slave-traders who brought him to this continent where he was owned by Colonel William Spencer." According to James McCune Smith, Garnet's father was George Trusty and his enslaved mother was "a woman of extraordinary energy."

In 1824, the family, which included a total of 11 members, secured permission to attend a funeral, and from there they all escaped in a covered wagon, via Wilmington, Delaware, where they were helped by the Quaker and Underground Railroad stationmaster Thomas Garrett.^{[citation needed]}