He was educated at the Cantonal Gymnasium in Zürich and at the Eidgenössische Technische Hochschule (ETHZ), also in Zürich. Initially studying engineering he soon changed to physics. During this time he attended lectures and seminars given by Peter Debye and Hermann Weyl at ETH Zürich and Erwin Schrödinger at the neighboring University of Zürich. A fellow student in these seminars was John von Neumann. Bloch graduated in 1927, and was encouraged by Debye to go to Leipzig to study with Werner Heisenberg. Bloch became Heisenberg's first graduate student, and gained his doctorate in 1928. His doctoral thesis established the quantum theory of solids, using Bloch waves to describe electrons in periodic lattices.

He remained in European academia, working on Superconductivity with Wolfgang Pauli in Zürich; with Hans Kramers and Adriaan Fokker in Holland; with Heisenberg on ferromagnetism, where he developed a description of boundaries between magnetic domains, now known as "Bloch walls"; with Niels Bohr in Copenhagen, where he worked on a theoretical description of the stopping of charged particles traveling through matter; and with Enrico Fermi in Rome. In 1932, Bloch returned to Leipzig to assume a position as "Privatdozent" (lecturer). In 1933, immediately after Hitler came to power, he left Germany because he was Jewish, returning to Zürich, before traveling to Paris to lecture at the Institut Henri Poincaré.

In 1934, the chairman of Stanford Physics invited Bloch to join the faculty. Bloch accepted the offer and emigrated to the United States. In the fall of 1938, Bloch began working with the 37" cyclotron at the University of California at Berkeley to determine the magnetic moment of the neutron. Bloch went on to become the first professor for theoretical physics at Stanford. In 1939, he became a naturalized citizen of the United States.

In 1940 he married Lore Misch, a Physicist working on X-ray crystallography, whom he had met at an American Physical Society meeting. The couple had four children.

After the war, he concentrated on investigations into nuclear induction and nuclear magnetic resonance, which are the underlying principles of MRI. In 1946 he proposed the Bloch equations which determine the time evolution of nuclear magnetization. Along with Edward Purcell, Bloch was awarded the 1952 Nobel Prize in Physics for his work on nuclear magnetic induction.

When CERN was being set up in the early 1950s, its founders were searching for someone of the stature and international prestige to head the fledgling international laboratory, and in 1954 Professor Bloch became CERN's first Director-General, at the time when construction was getting under way on the present Meyrin site and plans for the first machines were being drawn up. After leaving CERN, he returned to Stanford University, where he in 1961 was made Max Stein Professor of Physics.

In 1964, he was elected a foreign member of the Royal Netherlands Academy of Arts and Sciences.