Frederick Douglass (born Frederick Augustus Washington Bailey, c. February 14, 1818 – February 20, 1895) was an American social reformer, abolitionist, orator, writer, and statesman. He was the most important leader of the movement for African-American civil rights in the 19th century.

After escaping from slavery in Maryland in 1838, Douglass became a national leader of the abolitionist movement in Massachusetts and New York and gained fame for his oratory and incisive antislavery writings. Accordingly, he was described by abolitionists in his time as a living counterexample to claims by supporters of slavery that enslaved people lacked the intellectual capacity to function as independent American citizens. Northerners at the time found it hard to believe that such a great orator had once been enslaved. It was in response to this disbelief that Douglass wrote his first autobiography.

Douglass wrote three autobiographies, describing his experiences as an enslaved person in his Narrative of the Life of Frederick Douglass, an American Slave (1845), which became a bestseller and was influential in promoting the cause of abolition, as was his second book, My Bondage and My Freedom (1855). Following the Civil War, Douglass was an active campaigner for the rights of freed slaves and wrote his last autobiography, Life and Times of Frederick Douglass. First published in 1881 and revised in 1892, three years before his death, the book covers his life up to those dates. Douglass also actively supported women's suffrage, and he held several public offices. Without his knowledge or consent, Douglass became the first African American nominated for vice president of the United States, as the running mate of Victoria Woodhull on the Equal Rights Party ticket.

Douglass believed in dialogue and in making alliances across racial and ideological divides, as well as, after breaking with William Lloyd Garrison, in the anti-slavery interpretation of the U.S. Constitution. When radical abolitionists, under the motto "No Union with Slaveholders", criticized Douglass's willingness to engage in dialogue with slave owners, he replied: "I would unite with anybody to do right and with nobody to do wrong."

Frederick Augustus Washington Bailey was born into slavery on the Eastern Shore of the Chesapeake Bay in Talbot County, Maryland. The plantation was between Hillsboro and Cordova; his birthplace was likely his grandmother's cabin east of Tappers Corner and west of Tuckahoe Creek. In his first autobiography, Douglass stated: "I have no accurate knowledge of my age, never having seen any authentic record containing it." In successive autobiographies, he gave more precise estimates of when he was born, his final estimate being 1817. However, based on the extant records of Douglass's former owner, Aaron Anthony, historian Dickson J. Preston determined that Douglass was born in February 1818. Though the exact date of his birth is unknown, he chose to celebrate February 14 as his birthday, remembering that his mother called him her "Little Valentine".

Douglass's enslaved mother was of African descent and his father, who may have been her master, was apparently of European descent; in his Narrative (1845), Douglass wrote: "My father was a white man." According to David W. Blight's 2018 biography of Douglass, "For the rest of his life he searched in vain for the name of his true father." Douglass's genetic heritage likely also included Native American. Douglass said his mother Harriet Bailey gave him his name Frederick Augustus Washington Bailey and, after he escaped to the North in September 1838, he took the surname Douglass, having already dropped his two middle names.

He later wrote of his earliest times with his mother:

The opinion was also whispered that my master was my father; but of the correctness of this opinion, I know nothing. ... My mother and I were separated when I was but an infant. ... It is a common custom, in the part of Maryland from which I ran away, to part children from their mothers at a very early age. ... I do not recollect of ever seeing my mother by the light of day. She was with me in the night. She would lie down with me, and get me to sleep, but long before I waked she was gone.