Philip B. Moon is a British physicist

He worked at Cavendish Laboratory in the mid-1930s, where he shared a room with Australian phyicist Mark Oliphant. Both later joined Birmingham University, Moon in 1938.

During World War II Moon was part of the British delegation to the Manhattan Project, where amongst other things he did work on designing instrumentation for measuring the eventual bomb test.

After the war he was made Poynting Professor of Physics at Birmingham in 1946, succeeding Oliphant but receiving the appointment only after the first choice (Cecil Powell) had been rejected at the last minute for being a communist. He held the position until 1973.

In 1950 Moon was the first person to detect gamma ray fluorescence. However his results were not considered statistically significant enough and it would be several years before they were proven.

In 1991, Moon was the recipient of the Hughes Medal from the Royal Society.