Thomas Garrett (August 21, 1789 – January 25, 1871) was an American abolitionist and leader in the Underground Railroad movement before the American Civil War.
Garrett was born into a prosperous landowning Quaker family on their homestead called "Riverview Farm" in Delaware County, Pennsylvania. When Thomas was a boy, one of the family's free black female servants was kidnapped by men who intended to sell her into slavery in the South. The Garrets rescued her, but this incident confirmed them in their abolitionist views, and all the sons would later become involved in abolitionism, and Thomas on a very large scale.
When their father died in 1839, the original farm was split between Thomas' brothers' Issac and Edward, who renamed their farms "Fernleaf Farm" and "Cleveland Farm", but much is preserved today as Arlington Cemetery, Thomas' house, "Thornfield" built around 1800 and in which he lived until 1822, still stands today (as a private residence) in what is now Drexel Hill in Upper Darby Township.
In the schism between Orthodox and Hicksite Quakers, Garrett split with his Orthodox family and moved to Wilmington in the neighboring slave state of Delaware to strike out on his own and pursue his struggle against slavery. He established an iron and hardware business and made it prosper.
In 1827 Society of the State of Delaware was reorganized as the Delaware Abolition Society, whose officers and directors included Garrett, William Chandler, president John Wales, vice-president Edward Worrell, and others. Later that year, Wales and Garrett represented the group at the National Convention of Abolitionists.