Romeo Montague (Italian: Romeo Montecchi) is the male protagonist of William Shakespeare's tragedy Romeo and Juliet. The son of Lord Montague and his wife, Lady Montague, he secretly loves and marries Juliet, a member of the rival House of Capulet, through a priest named Friar Laurence.

Forced into exile after slaying 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 reworked in 1524 by Luigi da Porto as Giulietta e Romeo (published posthumously in 1531). Da Porto named the character Romeo Montecchi and his storyline is near-identical to Shakespeare's adaptation. Since no 16th-century direct English translation of Giulietta e Romeo is known, Shakespeare's main source is thought to be Arthur Brooke's English verse translation of a French translation of a 1554 adaptation by Matteo Bandello. 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.