The novel tells the story of five families— the Bezukhovs, the Bolkonskys, the Rostovs, the Kuragins, and the Drubetskoys.
The main characters are:
- Count Pyotr Kirillovich (Pierre) Bezukhov: The central character and often a voice for Tolstoy's own beliefs or struggles. Pierre is the socially awkward illegitimate son of Count Kirill Vladimirovich Bezukhov, who has fathered dozens of illegitimate sons. Educated abroad, Pierre returns to Russia as a misfit. His unexpected inheritance of a large fortune makes him socially desirable.
- Prince Andrei Nikolayevich Bolkonsky: A strong but skeptical, thoughtful and philosophical aide-de-camp in the Napoleonic Wars.
- Princess Maria Nikolayevna Bolkonskaya: Sister of Prince Andrei, Princess Maria is a pious woman whose father attempted to give her a good education. The caring, nurturing nature of her large eyes in her otherwise plain face are frequently mentioned.
- Count Ilya Andreyevich Rostov: The pater-familias of the Rostov family; hopeless with finances, generous to a fault. As a result the Rostovs never have enough cash, in spite of having many estates.
- Countess Natalya Rostova: Wife of Count Ilya Andreyevich Rostov
- Countess Natalya Ilyinichna (Natasha) Rostova: A central character, introduced as "not pretty but full of life", romantic, impulsive and highly strung. She is an accomplished singer and dancer.
- Count Nikolai Ilyich (Nikolenka) Rostov: A hussar, the beloved eldest son of the Rostov family.
- Sofia Alexandrovna (Sonya) Rostova: Orphaned cousin of Vera, Nikolai, Natasha, and Petya Rostov.
- Countess Vera Ilyinichna Rostova: Eldest of the Rostov children, she marries the German career soldier, Berg.
- Pyotr Ilyich (Petya) Rostov: Youngest of the Rostov children.
- Prince Vasily Sergeyevich Kuragin: A ruthless man who is determined to marry his children well at any cost.
- Princess Elena Vasilyevna (Hélène) Kuragina: A beautiful and sexually alluring woman who has many affairs, including (it is rumoured) with her brother Anatole.
- Prince Anatole Vasilyevich Kuragin: Hélène's brother, a handsome and amoral pleasure seeker who is secretly married yet tries to elope with Natasha Rostova.
- Prince Ippolit Vasilyevich: The eldest and perhaps most dim-witted of the three Kuragin children.
- Prince Boris Drubetskoy: A poor but aristocratic young man driven by ambition, even at the expense of his friends and benefactors, who marries Julie Karagina for money.
- Princess Anna Mihalovna Drubetskaya: The impoverished mother of Boris, whom she wishes to push up the career ladder.
- Fyodor Ivanovich Dolokhov: A cold, almost psychopathic officer, he ruins Nikolai Rostov by luring him into an outrageous gambling debt.
- Adolf Karlovich Berg: A young Russian officer, who desires to be just like everyone else.
- Anna Pavlovna Scherer: Also known as Annette, she is the hostess of the salon that is the site of much of the novel's action in Petersburg.
- Maria Dmitryevna Akhrosimova: An older Moscow society lady, she is an elegant dancer and trend-setter, despite her age and size.
- Amalia Evgenyevna Bourienne: A French woman who lives with the Bolkonskys, primarily as Princess Maria's companion.
- Vasily Dmitrich Denisov: Nikolai Rostov's friend and brother officer, who proposes to Natasha.
- Platon Karataev: The archetypal good Russian peasant, whom Pierre meets in the prisoner of war camp.
- Osip Bazdeyev: the Freemason who interests Pierre in his mysterious group, starting a lengthy subplot.
In addition several real-life historical characters (such as Napoleon) play a prominent part in the book. Many of Tolstoy's characters were based on real people. His grandparents and their friends were the models for many of the main characters; his great-grandparents would have been of the generation of Prince Vassily or Count Ilya Rostov.
