Lewis Lambert Strether
an American, from Woollett Massachusetts, who is in his late middle age. Strether works for the wealthy Mrs. Newsome. She has sent Strether to Paris with the task of retrieving her son Chadwick Newsome (Chad). Chad has been in Paris for three years, apparently living the life of a wastrel. Once in Paris, Strether is sidetracked and he ultimately fails to do Mrs. Newsome's bidding. Strether evaluates his life and wonders whether he has truly lived. Sensing his own regret, Strether advises Chad against returning home to become a mere "man of business."
Chadwick Newsome (Chad)
Chad is the son of Mrs. Newsome, and he remains in Paris until his sister, Sarah Pocock, arrives on scene to bring him home. Chad is befriended by two young Americans, Little Bilham and Miss Barrace. Chad has also become romantically involved with Madame de Vionnet - a Countess who is already married and significantly older than Chad. Chad's friends help to convince Strether that Chad has "improved" in Paris - but ultimately, Paris cannot hold Chad. He has had his adventure and at the end of the novel, Chad content to return home and enter the family business.
Maria Gostrey
an American woman living in Europe. She takes the voluntary duty of educating and assisting Americans in Europe who appear "lost." Gostrey finds Strether almost immediately in England and throughout the novel, she helps him make sense of his situation. Ultimately, Gostrey makes a half-hearted and late bid for romance with Strether, but both characteres realize that such a relationship is impossible.
Madame de Vionnet
a French countess who is separated from her husband. De Vionnet enjoys a romantic relationship with Chad, who is significantly younger than she is. When the relationship wanes, the countess looks to marry Chad to her daughter, Jeanne. Chad refuses this but does help Madame de Vionnet find a more suitable spouse for Jeanne. De Vionnet charms Strether and succeeds in winning more time with Chad. By the end of the novel, Chad has left Madame de Vionnet and returned to America.
Waymarsh
Strether's traveling companion and old friends from Milrose, Connecticut. Waymarsh is a lawyer with a rigid and sensitive moral sense. He continually warns Strether not to dabble in Parisian society and even urges Strether to give up his mission - rather than subvert it. Quite disgusted by Strether's behavior, Waymarsh leaves with the Pococks, essentially abandoning Strether in Europe.
Mrs. Newsome
a wealthy invalid widow who lives in Woollett, Massachusetts. Her son, Chad, is in Paris and she has sent her employee (Strether) to retrieve him. Strether has the opportunity to marry Mrs. Newsome, who is rather fond of him. Strether forfeits this opportunity by betraying Mrs. Newsome's interests, however. In the end, Mrs. Newsome sends her daughter Sarah Pocock (along with Sarah's husband, Jim, and Jim's sister, Mamie) to finish the job. Without much trouble, Sarah brings Chad home.
Sarah Pocock
the daughter of Mrs. Newsome and wife of Jim Pocock, Sarah is a strong-willed individual. Sent as the replacement ambassador, Sarah dedicates herself to her task, never wavering. Sarah is patient and forgiving of Strether, offering him a generous opportunity to redeem himself. To Sarah's shock, Strether is rather insulting and ungrateful, rejecting Sarah's bargain and essentially sealing his own sad fate. Even without Strether's symbolic help, Sarah carries her brother home all the same.
Jim and Mamie Pocock
these two siblings have become part of the Newsome family, and they accompany Sarah Pocock to Paris. Jim is married to Mrs. Newsome's daughter, Sarah, and there is talk of Mamie being wed to Chad Newsome. Though it is not confirmed, this outcome seems all the more likely by the end of the novel.
Gloriani
a sculptor who appears in James' novel Roderick Hudson. In The Ambassadors, Gloriani hosts a well-attended garden party.
John Little Bilham and Miss Barrace
two of Chad's closest friends in Paris. Young Americans, Bilham and Barrace win the trust of Strether and the sympathy of Maria Gostrey. At the end of the novel, Bilham and Barrace leave as part of the exodus of Americans.
Jeanne de Vionnet
the daughter of the Count and Countess de Vionnet (Madame de Vionnet). Jeanne is extremely "cosmopolitan" and well-educated. Jeanne's mother makes a bid to marry Jeanne to Chad Newsome, but instead Jeanne is engaged to a young Frenchman.
