Allen, John Frank (1908-2001) was a British physicist who studied low temperatures. He also was a university administrator who championed students' rights.

Allen received his undergraduate degree in 1928 from the University of Manitoba. In 1929, he received a scholarship to attend the University of Toronto. While working on his doctorate, Allen designed a glass apparatus that could hold liquid helium. Allen's adviser, J. C. McLennan, used the device to demonstrate superconductivity at the Royal Institution in London. The apparatus now resides in the institution's museum.

In 1935, Allen moved to the Royal Society Mond Laboratory in Cambridge, hoping to collaborate with Pyotr Kapitsa, a well-known physicist who studied low temperature. Their partnership never happened. On a visit to his native Russia, Kapitsa was detained and not permitted to leave. The two scientists continued their research independently. In 1938 they both sent letters to Nature reporting that liquid helium flowed quickly through narrow holes that it would not be able to flow through at higher temperatures. Kapitsa coined the term “superfluid” to describe this phenomenon.

Allen left Cambridge in 1947 to become professor of natural philosophy at the University of St. Andrews, a job he held until 1978. As a teacher, he conducted lively presentations to entertain and educate students. At very low temperatures, helium becomes a liquid with unusual behavior, such as flowing up against gravity. Allen made a movie, Superfluid Helium, in which he showed how liquid helium could create a fountainlike effect.

He twice served as dean of the faculty of science. In his administrative role, Allen implemented reforms, such as a student-staff council, that was the first organization of its kind. He also fought to ensure that students had a voice in university matters.

Allen married Elfriede Hiebert in 1933. The couple adopted a son before divorcing in 1951.