"The Twelve Brothers" (German: Die zwölf Brüder) is a German fairy tale collected by the Brothers Grimm in Grimm's Fairy Tales (KHM 9). Andrew Lang included it in The Red Fairy Book. 

It is of Aarne-Thompson type 451 ("The Brothers Who Were Turned into Birds"), which is commonly found throughout Europe.  Other variants of the Aarne-Thompson type include The Six Swans, The Twelve Wild Ducks, Udea and her Seven Brothers, The Wild Swans, The Seven Ravens, and The Magic Swan Geese.

The tale was published by the Brothers Grimm in the first edition of Kinder- und Hausmärchen in 1812, and substantially rewritten in the second edition (1819). Their sources were Julia R. Ramus (1792–1862) and Charlotte R. Ramus (1793–1858).