The Blue-capped Hummingbird or Oaxaca Hummingbird (Eupherusa cyanophrys) is a species of hummingbird endemic to subtropical moist forest in the southernmost portion of the Sierra Madre del Sur in the Mexican state of Oaxaca. Its tiny range is threatened by habitat loss.

Like White-tailed Hummingbird, it is sometimes considered a subspecies of the more widespread Stripe-tailed Hummingbird.