The Blue Manakin or Swallow-tailed Manakin (Chiroxiphia caudata) is a species of bird in the Pipridae family. It is found in north-eastern Argentina, southern and south-eastern Brazil, and Paraguay.

Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montane forests, and heavily degraded former forest. It is generally common in the appropriate habitats within its range. Formerly, the name Swallow-tailed Manakin was used widely, but as it is misleading (the tail is unlike that of any swallow), this name has largely been abandoned for the superior Blue Manakin. As suggested by this common name, the male is - by far - the manakin with most blue to the plumage. The entire body is bright blue, while the wings, tail and head, except for the red cap, are black. The far duller female is greenish overall. Both sexes have elongated central rectrices. Juvenile males resemble the adult female, but gradually develop first the red crown, then the black face-sides, and finally the remaining plumage of the adult male. The males form leks, typically consisting of a single adult and two sub-adult males, where they sing and "dance" to attract females.