John Henry Lienhard IV (born August 17, 1930) is Professor Emeritus of mechanical engineering and history at The University of Houston.

He worked in heat transfer and thermodynamics for many years prior to creating the radio program The Engines of Our Ingenuity.

One of his great-grandfathers was the Swiss pioneer Heinrich Lienhard, and another was the abolitionist, newspaper editor, and Minnesota state legislator Charles Augustus Wheaton.

He then received a BS degree from the Oregon State College (1951), after which he worked for the Boeing Airplane Co. in Seattle, Washington.

He continued his studies in mechanical engineering, earning his MS degree from the University of Washington (1953) before being drafted into the US Army.

His work on critical heat flux included centrifuge measurements of boiling at high gravity, some conducted for NASA.

Over the three decades after Engines launched, Lienhard gave dozens of invited lectures each year, eventually totaling more than 1100 major addresses.

[1] He donated the honoraria from these talks to the University of Houston to create the Engines of Our Ingenuity undergraduate scholarship endowment.