Leo A. Ohlinger was a senior engineer at the University of Chicago Met Lab. Ohlinger was also Section Chief of P-IX, Engineering Physics.
He worked in the Theoretical Group under Eugene Wigner and was involved in the design of water-cooled production reactors. These designs were the basis for the production reactors at Hanford.
Ohlinger later shared the patent for the design of the reactors. He was also a signer of the Szilard Petition.