London was born in Breslau, now Wrocław in Poland, the son of a mathematics professor at Bonn and the elder brother of the well-known physicist, Heinz London. He originally received a classical education at the Universities of Frankfurt, Munich, and Bonn, where in 1921 he was awarded his doctorate for a philosophical thesis. London taught in secondary schools for some years and then began work as a physicist in 1925 at Munich. After appointments in Stuttgart, Zurich, and Berlin he left Germany in 1933 with the rise of Hitler. He worked first in the Clarendon Laboratory in Oxford and from 1935 at the Institut Poincaré, Paris, before moving to America to become professor of theoretical chemistry at Duke University, North Carolina – a post he retained until his death in 1954.

In 1927 London, in collaboration with Walter Heitler, succeeded in providing an account of the covalent bond in the hydrogen molecule using wave mechanics. In the 1930s he collaborated with his brother in gaining a major insight into the nature of superconductivity. This was followed by his own researches, beginning in 1938, into the nature of superfluidity, a phenomenon first described by Pyotr Kapitza.