The Hornby's storm petrel or ringed storm petrel (Oceanodroma hornbyi) is a seabird that ranges in the Humboldt Current off the coasts of South America. The species is a very distinctive member of the storm petrel family, with a dark cap, white face and underparts, forked tail and a black band across the chest. It is relatively common in the seas off Peru, Chile and Ecuador. The species is named after Admiral Sir Phipps Hornby.