Kim is the 13-year-old orphaned son of an Irish regimental soldier, raised as a street child in Lahore. Known locally as the "Little Friend of all the World," he operates with a bright, boyish charisma and a talent for blending into the diverse cultures of British India. He carries an amulet containing his birth certificate and Masonic documents, which hint at his hidden European heritage. His natural curiosity draws him into both spiritual quests and dangerous espionage operations.

The Lama is an elderly Tibetan Buddhist holy man and former abbot from the northern hill country. He journeys across India seeking the legendary Arrow River, which he believes will grant him enlightenment and freedom from the "Wheel of Things." He views the world with patient detachment and relies heavily on Kim to handle the practical matters of their journey.

Mahbub Ali is a Muslim horse trader from Lahore who secretly operates as an agent for the British intelligence network. He frequently travels for commerce, using his business as a cover to gather and pass on geopolitical information in "the Great Game." He enlists Kim as a messenger and acts as a practical mentor for the boy's entry into espionage.

Hurree Babu is an Indian agent working for the British ethnographic survey, which doubles as an intelligence agency. He often disguises himself as a Hindu healer despite his actual agnostic beliefs. He is highly skilled in espionage and deeply passionate about his ethnological work, hoping to gain formal recognition from British academic societies.

Colonel Creighton is a British military officer and ethnologist who oversees intelligence operations in India. Unlike many British colonial officials, he possesses a deep understanding of Indian culture and operates with a cautious, measured approach. He recognizes Kim's potential and arranges for his formal schooling and espionage training.

The Kulu Woman is the sharp-tongued but hospitable widow of a northern hill-rajah. She travels toward Buddh Gaya and crosses paths with Kim and The Lama along the road, offering them lodging and food in exchange for a blessing for her hoped-for grandson.

The Woman of Shamlegh is a local woman from the northern hills who provides shelter to Kim and The Lama after a violent altercation. She harbors a sense of betrayal after being abandoned by a British officer years earlier, presenting a realistic and unromanticized view of the world.

Lurgan is a white man operating as a dealer in jewels and curiosities in Simla. Thoroughly immersed in Indian culture and mysticism, he trains Kim in observation and disguise, utilizing exercises like the "Jewel Game" to prepare the boy for intelligence work.

Father Victor is a Catholic chaplain attached to the Mavericks, the Irish regiment in which Kim's father served. Upon discovering Kim's European heritage, he takes an active role in trying to secure the boy's formal education and integration into British society.

Reverend Arthur Bennett is an Anglican clergyman attached to the Mavericks regiment. He catches Kim sneaking into the camp and initially assumes the boy is a thief before discovering the amulet containing Kim's birth papers.

E23 is a Mahratta secret agent working for the British. He encounters Kim on a train while fleeing from adversaries, covered in injuries and desperate for a disguise to escape detection and pass on vital information.

A young boy living with Lurgan in Simla. He is initially intensely jealous of Kim but proves useful by competing against him in the "Jewel Game," a memory and observation exercise used for espionage training.

Huneefa is a woman who assists the intelligence network by using dyes to alter Kim's skin color, completing his disguise as a native Indian. She also performs a magical incantation over him for spiritual protection.

The Russian is a foreign agent operating in the northern hills to undermine British influence. Culturally insensitive, he attempts to buy and then forcefully takes a sacred drawing from The Lama, sparking a chaotic physical altercation.

The Frenchman is a foreign agent working alongside The Russian. He lacks an understanding of local customs and relies heavily on native servants to travel through the hills.

Kimball O'Hara is Kim's deceased father, a former sergeant in the Irish Mavericks regiment who later worked on the Delhi Railway. Before succumbing to opium addiction, he left behind papers and a prophecy about a Red Bull on a green field.