Henry Adams The central figure of the book is especially interested in history, writing, modern science, the Middle Ages, and various aspects of education.
John Quincy Adams The sixth President of the United States is important here as a role model and loving paternal grandfather to Henry.
Louisa Catherine (Johnson) Adams Known affectionately as "The Madam," Henry's grandmother provides a stable center to his summer visits at Quincy.
Charles Francis Adams Professionally, Henry is especially close to his father and serves as his personal secretary in both Washington and London.
Abigail Brown (Brooks) Adams Patient and proper, Henry's mother is from one of the most prestigious families in Boston.
Charles Francis Adams, Jr. This close older brother encourages Henry to become a writer and teams with him in exposing the Gold Conspiracy of 1869.
Louisa Catherine (Adams) Kuhn The death of Henry's beloved older sister from tetanus, following a cab accident near her home in Italy, is one of the most poignant moments in the Education.
John Hay Secretary of State from 1898 to his death in 1905, Hay is one of Henry's closest friends; the two build houses next to each other in Washington.
Clarence King After meeting during a geological expedition to Estes Park in 1871, King and Adams become close friends. Henry judges King to be the brightest and best of their generation and is greatly disturbed by King's tragic end.
Elizabeth Cameron The wife of a U. S. Senator from Pennsylvania, Elizabeth becomes Henry's emotional confidante after his wife, Marian's, suicide, an event not mentioned in the Education.
John La Farge An artist well known for his murals and stained glass windows, La Farge travels extensively, most notably to the South Seas, with his friend Henry after Marian's suicide.
The Terrible Conky Daniels A notorious ruffian and leader of the slum "blackguards" in a monumental snowball fight (see Chapter III of the Critical Commentaries), Conky teaches Henry an important lesson about class distinction and chivalry.
William H. Seward Secretary of State during Charles Francis Adams's tenure as Minister to England, Seward impresses Henry with his practicality, opposition to slavery, and support of Henry's father.
Jay Gould His attempt to corner the gold market in September 1869 provides Henry with a wonderful opportunity for reform journalism.
President Ulysses S. Grant Henry finds Grant to be an incompetent, do-nothing president, but Grant's administration allows Henry to advance his reputation as a political journalist.
President Abraham Lincoln Initially unimpressed by the rustic statesman, Henry grows to respect Lincoln's depth and capacity for growth.
Palmerston, Russell, and Gladstone These British politicians broaden Henry's education regarding political morality and practical politics (see Chapter X of the Critical Commentaries).
Sir Charles Lyell A leading English geologist, Lyell helps introduce Henry to Darwinism and the theories of evolution.