Queen Mab is a fairy referred to in William Shakespeare's play Romeo and Juliet, where "she is the fairies' midwife". Later, she appears in other poetry and literature, and in various guises in drama and cinema. In the play, her activity is described in a famous speech by Mercutio published originally in prose and often adapted into iambic pentameter, in which she is a miniature creature who performs midnight pranks upon sleepers. Being driven by a team of atomies, she rides her chariot over their noses and "delivers the fancies of sleeping men". She is also described as a midwife to help sleepers "give birth" to their dreams. Later depictions have typically portrayed her as the Queen of the Fairies.

Romeo and Juliet is a tragedy written by William Shakespeare early in his career about the romance between two Italian youths from feuding families. It was among Shakespeare's most popular plays during his lifetime and, along with Hamlet, is one of his most frequently performed. Today, the title characters are regarded as archetypal young lovers.