John Woolman (October 19, 1720 (O.S.)/October 30, 1720 (N.S.)– October 7, 1772) was an American merchant, tailor, journalist, Quaker preacher, and early abolitionist during the colonial era. Based in Mount Holly, New Jersey, near Philadelphia, he traveled through the American frontier to preach Quaker beliefs, and advocate against slavery and the slave trade, cruelty to animals, economic injustices and oppression, and conscription. Beginning in 1755 with the outbreak of the French and Indian War, he urged tax resistance to deny support to the colonial military. In 1772, Woolman traveled to England, where he urged Quakers to support abolition of slavery.

Woolman published numerous essays, especially against slavery. He kept a journal throughout his life; it was published posthumously, entitled The Journal of John Woolman (1774). Included in Volume I of the Harvard Classics since 1909, it is considered a prominent American spiritual work. It has also been admired for the power and clarity of its prose by non-Quakers such as the philosopher John Stuart Mill, the poet William Ellery Channing, and the essayist Charles Lamb, who urged a friend to "get the writings of John Woolman by heart." The Journal has been continuously in print since 1774, published in numerous editions; the most recent scholarly edition was published in 1989.

John Woolman was born in 1720, originally from Rancocas, New Jersey, into a family who were members of the Religious Society of Friends (Quakers). His father, Samuel Woolman, was a farmer. The 150-acre Woolman farm sat on the north bank of the north branch of Rancocas Creek close to the western border of Rancocas State Park. Woolman's maternal and paternal grandparents were early Quaker settlers in Burlington County, New Jersey.

During his youth, he happened upon a robin's nest that held hatchlings. Woolman began throwing rocks at the mother robin to see if he could hit her. After killing the mother bird, he was filled with remorse, thinking of the baby birds who had no chance of survival without her. He got the nest down from the tree and quickly killed the hatchlings, believing it to be the most merciful thing to do. This experience weighed on his heart. He was inspired to love and protect all living things from then on.

Woolman married Sarah Ellis, a fellow Quaker, in a ceremony at the Chesterfield Friends Meeting, and they had a daughter whom they named Mary. His choice to lead a "life of simplicity" meant making sacrifices for his family.

As a young man, Woolman began work as a clerk for a merchant. When he was 23, his employer asked him to write a bill of sale for an enslaved person. Though he told his employer that he thought that slaveholding was inconsistent with Christianity, he wrote the bill of sale.

By the age of 26, he had become an independent and successful tradesman. He refused to write the part of another customer's will which would have bequeathed or transferred the ownership of a slave, and instead convinced the owner to set the enslaved person free by manumission. Many Friends (fellow Quakers) believed that slavery was a sin. Other Friends kept slaves but considered trading in slaves to be sinful.

Woolman eventually retired from business (i.e., "merchandising") because he viewed profit-making as distracting from his religion. He wrote that he took up the trade of tailor in order to have more free time to travel and witness to fellow Quakers about his concerns.