Captain Ramius is a respected, veteran Soviet submarine commander of Lithuanian descent. He enjoys immense trust within the Soviet Navy, having taken every new submarine on its first voyage for the past decade. Driven by the preventable death of his wife due to state incompetence and corruption, he plots a treasonous defection to the United States alongside his handpicked officers, using the advanced Red October submarine as his bargaining chip.

Jack Ryan is a former Marine turned CIA analyst who writes history books and strongly prefers his desk job over fieldwork. He suffers from a deep fear of flying following a severe helicopter crash during his military service. When he reviews photographs of the Red October's unusual hull doors, his keen analytical skills push him into a tense, high-stakes assignment at sea to verify his theory about the submarine captain's intentions.

Ronald Jones is a young, slightly rebellious sonar operator who was expelled from the California Institute of Technology following a prank. Working aboard the attack submarine USS Dallas, he uses his exceptional hearing and passion for music to detect the nearly silent caterpillar drive of the Red October. He trusts his own senses over the submarine's computer systems, which incorrectly identify the noise as magma displacement.

Commander Mancuso is the captain of the USS Dallas. The son of an Illinois barber, he graduated from Annapolis and achieved a submarine command at a remarkably young age. He possesses a deep understanding of naval warfare and demonstrates a willingness to risk pursuing an unidentified, silent submarine based on the specialized skills of his crew.

Tupolev is the ambitious captain of the Soviet submarine VK Konovalov. As a former student of Marko Ramius, he is initially assigned to test his skills against his old teacher in a training exercise. When the Soviet Navy realizes Ramius's true intentions, Tupolev's mission changes to a lethal hunt, driven by a deep desire to prove he is now the superior commander.

Vice Admiral Greer serves as the Deputy Director of Intelligence for the CIA. He relies heavily on Ryan's analytical skills and facilitates his access to high-level resources. He operates as a crucial bridge between CIA analysts working behind desks and the top military and political leaders making operational decisions.

Tyler is a former naval officer currently teaching at Annapolis. He uses his extensive background in engineering to identify the Red October's silent tunnel drive system. Utilizing a Pentagon supercomputer, he runs simulations that confirm the submarine's threat level and formulates a strategic plan to extract the defecting crew safely.

The President manages the American response to the sudden, aggressive mobilization of the Soviet Naval Fleet. He balances the incredible intelligence opportunity of capturing a state-of-the-art Soviet submarine against the severe risk of sparking a global conflict. He strictly controls the diplomatic dialogue, using careful political maneuvering to obscure American intentions.

Arbatov serves as the diplomatic face of the Soviet Union in Washington, D.C. He is tasked with delivering state-mandated cover stories—such as a search-and-rescue mission for a missing submarine—to obscure the true nature of their massive naval deployment and prevent the Americans from seizing the Red October.

Vice Admiral White commands the British aircraft carrier Invincible. He uses his vessel and authority to assist the Americans in searching for the Red October under the guise of participating in an international rescue operation.

Putin is the designated political officer assigned to the Red October on its maiden voyage. Representing the watchful eye of the Soviet state, his explicit duty is to ensure the captain strictly adheres to Communist Party directives. This makes him the immediate, primary obstacle to any defection plans Ramius formulates.

Natalia is the late wife of Marko Ramius. Holding a literature degree, she taught him English and introduced him to independent ways of thinking. Her death from a preventable infection—caused by an intoxicated, highly connected surgeon and unregulated drugs—sparks her husband's intense desire for retribution against the Soviet government.

Svyadov is a young lieutenant aboard the Red October who is specifically excluded from Ramius's inner circle of defectors. He genuinely believes the submarine is suffering from a dangerous reactor leak, and his natural anxiety spreads panic among the enlisted men.

Peter Henderson is the chief aide to Senator Donaldson. He operates as an active spy, leaking classified American intelligence to the Soviet Union. The CIA detects his espionage and uses him to feed false information back to his Soviet handlers.

Arthur Moore serves as the Director of Central Intelligence. He manages high-level espionage operations and oversees the complex strategy to safely secure the Red October while maintaining plausible deniability regarding American involvement.

Lieutenant Williams is a Russian-speaking British officer stationed aboard the Invincible. He accompanies Jack Ryan during the critical operation to board the Red October, providing necessary translation and operational support during the tense extraction.