Romeo Montague is one of the title characters in William Shakespeare's tragedy Romeo and Juliet. He serves as the play's male protagonist. Romeo, the son of Montague and his wife, secretly loves and marries Juliet, a member of the rival House of Capulet. Forced into exile by his slaying of Juliet's cousin, Tybalt, in a duel, Romeo commits suicide upon hearing falsely of Juliet's death.

The character's origins can be traced as far back as Pyramus, who appears in Ovid's Metamorphoses, but the first modern incarnation of Romeo is Mariotto in the 33rd of Masuccio Salernitano's Il Novellino (1476). This story was adapted by Luigi da Porto as Giulietta e Romeo (1530), and Shakespeare's main source was an English verse translation of this text by Arthur Brooke. Although both Salernitano and da Porto claimed that their stories had historical basis, there is little evidence that this is the case.

Romeo, an only child like Juliet, is one of the most important characters of the play, and has a consistent presence throughout it. His role as an idealistic lover has led the word "Romeo" to become a synonym for a passionate male lover in various languages. Although often treated as such, it is not clear that "Montague" is a surname in the modern sense.