Grantaire is a fictional character from the 1862 novel Les Misérables by Victor Hugo. He is a student from the South of France and is one of the principal characters of the revolutionary group known as the Friends of the ABC. According to the novel, the Friends of the ABC only tolerate him because of his good humour, and he only joins because of his veneration of the leader, Enjolras. He often signs with his rebus: R and, at one point, Bossuet calls him "Capital R." He is a gambler and often drunk.

Les Misérables is a French historical novel by Victor Hugo, first published in 1862, that is considered one of the greatest novels of the 19th century. Les Misérables has been popularized through numerous adaptations for film, television and the stage, including a musical.