William Hayward Pickering ONZ KBE (24 December 1910 – 15 March 2004) was a New Zealand-born aerospace engineer who headed Pasadena, California's Jet Propulsion Laboratory (JPL) for 22 years, retiring in 1976.

After spending a year at the Canterbury University College, he moved to the United States (where he subsequently naturalized), to complete a bachelor's degree at the California Institute of Technology ("Caltech"), and later, in 1936, a PhD in Physics.

At the time of his retirement as director, in 1976, the Voyager missions were about to launch on tours of the outer planets and Viking 1 was on its way to land on Mars.

Between 1977 and his death in 2004, Pickering also served as Patron of the New Zealand Spaceflight Association; a non-profit organisation that existed from 1977 to 2012 to promote an informed approach to astronautics and related sciences.

[1] In 2009 to mark the International Year of Astronomy, William Hayward Pickering was selected along with cosmologist Beatrice Tinsley to have their names bestowed on peaks in the Kepler Mountains of New Zealand's Fiordland National Park.