The Tanimbar monarch (Carterornis castus), or Loetoe monarch is a bird in the family Monarchidae endemic to Indonesia. It is found in the Tanimbar Islands.
This subspecies was formerly placed in the genus Monarcha until moved to Carterornis in 2009.[1] While the Tanimbar monarch was formerly considered a subspecies of the white-naped monarch (C. pileatus), it is now considered a separate species.[2] [3]