The Yellow-rumped Flycatcher, Korean Flycatcher or Tricolor Flycatcher (Ficedula zanthopygia) is a species of flycatcher found in Asia. A distinctive species with almost no look-alike other than the Narcissus Flycatcher. It breeds in eastern Asia including parts of Mongolia, Transbaikal, southern China, Korea and western Japan. They winter in parts of the Malay Peninsula and South Asia.
In all plumages the yellow rump is distinctive. The white supercilium of the male is distinctive, separating it from the Narcissus Flycatcher and the Chinese Flycatcher. Females and first year males are olive grey above with blackish tail.
Hartert (1907) treated this as a part of the narcissina group. Some individuals with yellow supercilium have been considered as hybrids with the Narcissus Flycatcher. Included in this species complex was the species called Elise's Flycatcher. Weigold (1922) found this species to be distinct and found the elisae and zanthopygia species breeding in the same area in oak forest near Peking. There are also clear call and morphological difference between the two. The genus Muscicapa has been noted to have been polyphyletic and is still in the process of being resolved although the genus Ficedula is now considered monophyletic with their origins in east Asia, with diversification following climate changes in the Pliocene.
The breeding area of the species is in Eastern Asia. North Korea and China. From 1992, the species has been noted to winter in central India, southwestern India and Sri Lanka.
A species of feather mite, Proterothrix megacaula has been described as an ectoparasite of this bird.