"The Two Sisters" (also known by the Scots title "The Twa Sisters") is a traditional murder ballad, dating at least as far back as the mid 17th century. The song recounts the tale of a girl drowned by her jealous sister. At least 21 English variants exist under several names, including "Minnorie" or "Binnorie", "The Cruel Sister", "The Wind and Rain", "Dreadful Wind and Rain", "The Bonny Swans" and the "Bonnie Bows of London". The ballad was collected by renowned folklorist Francis J. Child as Child Ballad 10 and is also listed in the Roud Folk Song Index (Roud 8). Whilst the song is thought to originate somewhere around England or Scotland (possibly Northumbria), extremely similar songs have been found throughout Europe, particularly in Scandinavia.

Two sisters go down by a body of water, sometimes a river and sometimes the sea. The older one pushes the younger in and refuses to pull her out again; generally the lyrics explicitly state her intent to drown her younger sister. Her motive, when included in the lyrics, is sexual jealousy – in some variants, the sisters are being two-timed by a suitor; in others, the elder sister's affections are not encouraged by the young man. In a few versions, a third sister is mentioned, but plays no significant role in events. In most versions, the older sister is described as dark, while the younger sister is fair.

When the murdered girl's body floats ashore, someone makes a musical instrument out of it, generally a harp or a fiddle, with a frame of bone and the girl's "long yellow hair" (or "golden hair") for strings. The instrument then plays itself and sings about the murder. In some versions, this occurs after the musician has taken it to the family's household, so that the elder sister is publicly revealed (sometimes at her wedding to the murdered girl's suitor) as the murderer.

The American variant of "The Two Sisters" typically omits the haunted instrument entirely, ending instead with an unrelated person (often a miller) robbing the murdered girl's corpse, sometimes being executed for it, and the elder sister sometimes going unpunished, or sometimes boiled in lead.

It is first known to have appeared on a broadside in 1656 as "The Miller and the King's Daughter". Several historical resources are available via the Vaughan Williams Memorial Library, such as a manuscript of the melody and lyrics of a Scottish version entitled "Binnorie" from 1830.

Cecil Sharp collected many versions of the ballad on both sides of the Atlantic, including one from a Lucy Dunston of Bridgwater, Somerset, England in 1909, and another from a Jenny Combs of Berea, Kentucky, USA in 1917. Many authentic audio recordings have since been made (see Authentic Field Recordings).

The theme of this ballad was common in many northern European languages. There are 125 different variants known in Swedish alone. Its general Scandinavian classification is TSB A 38; and it is (among others) known as Den talende strengeleg or De to søstre (DgF 95), or Der boede en Mand ved Sønderbro in Danish, Hørpu ríma (CCF 136)in Faroese, Hörpu kvæði (IFkv 13) in Icelandic, Dei tvo systar in Norwegian, and De två systrarna (SMB 13) in Swedish. It has also spread further south; for example, as Gosli iz človeškega telesa izdajo umor (A Fiddle Made from a Human Body Reveals a Murder) in Slovenian.

In the Norse variants, the older sister is depicted as dark and the younger as fair, often with great contrast, comparing the former to soot and the other to the sun or milk. This can inspire taunts from the younger about the older's looks. However, in the Danish variant Der boede en Mand ved Sønderbro, the older sister takes the younger sister who has been intimate with a shared suitor down to a river indicating that they may both be washed clean (literally, 'white'), implying that the dark-light theme has broader implications; nevertheless the elder sister, in the act of drowning the younger over jealousy, thereby assumes upon herself any stain that could have been construed to have been upon the younger sister, as well as the act of murder which she has now committed.