Samuel Gridley Howe (November 10, 1801 – January 9, 1876) was an American physician, abolitionist, and advocate of education for the blind. He organized and was the first director of the Perkins Institution. In 1824, he went to Greece to serve as a surgeon in the Greek War of Independence. He arranged for support for refugees and brought many Greek children back to Boston with him for their education.

An abolitionist, Howe was one of three men appointed by the Secretary of War to the American Freedmen's Inquiry Commission, to investigate conditions of freedmen in the South since the Emancipation Proclamation and recommend how they could be aided in their transition to freedom. In addition to traveling to the South, Howe traveled to Canada West (now Ontario, Canada), where thousands of former slaves had escaped to freedom and established new lives. He interviewed freedmen as well as government officials in Canada.

Howe was born on Pearl Street in Boston, Massachusetts, on November 10, 1801. His father, Joseph Neals Howe, was a ship-owner and rope manufacturer in Boston. The business was prosperous until he supplied the U.S. Government with ropes during the war of 1812 and was never paid. His mother Patty (Gridley) Howe was considered to be one of the most beautiful women of her day. Samuel Gridley Howe's grandfather, Edward Compton Howe, was one of the patriots at the Boston Tea Party.

Howe was educated at Boston Latin School, where he was cruelly treated and even beaten, according to his daughter. Laura (Howe) Richards later wrote: "So far as I can remember, my father had no pleasant memories of his school days."

Boston in the early nineteenth century was a hotbed of political foment. Howe's father was a Democrat who considered Harvard University a den of Federalists, refusing to allow his sons to enter the university. Accordingly, Howe's father had him enrolled at Brown University in 1818. He engaged in many practical jokes and other high jinks and, years later, Howe told his children that he regretted that he hadn't more seriously applied himself to his studies. One of his classmates, Alexis Caswell, future doctor and president of Brown University described Howe as the following: "he showed mental capabilities which would naturally fit him for fine scholarship. His mind was quick, versatile, and inventive. I do not think he was deficient in logical power, but the severer studies did not seem to be congenial to him." After graduating from Brown in 1821, Howe attended Harvard Medical School, taking his degree in 1824.

Howe did not remain in Massachusetts for long after graduating. In 1824, shortly after Howe was certified to practice medicine, he became fired by enthusiasm for the Greek Revolution and the example of his idol, Lord Byron. Howe fled the memory of an unhappy love affair and sailed for Greece, where he joined the Greek army as a surgeon.

In Greece, his services were not confined to the duties of a surgeon but were of a more military nature. Howe's bravery, enthusiasm, and ability as a commander, as well as his humanity, won him the title "the Lafayette of the Greek Revolution." Howe returned to the United States in 1827 to raise funds and supplies to help alleviate the famine and suffering in Greece. Howe's fervid appeals enabled him to collect about $60,000, which he spent on provisions, clothing, and the establishment of a relief depot for refugees near Aegina. He later formed another colony for exiles on the Isthmus of Corinth. Afterward, Howe wrote an account of the revolt, Historical Sketch of the Greek Revolution, which was published in 1828. He brought back with him Lord Byron's helmet, which he later had on display in his house in Boston.

Samuel Gridley Howe brought many Greek refugee children back with him to the United States to educate them. Two who later gained prominence were John Celivergos Zachos, who became an abolitionist and activist for women's rights, and Christophorus P. Castanis. Castanis survived the Chios massacre. He later wrote a memoir about these events, The Greek Exile, Or, a Narrative of the Captivity and Escape of Christophorus Plato Castanis (1851). He mentioned both Dr. Howe and John Celivergos Zachos in this book.