The year 1933 in science and technology had many significant events, including those listed below.

Astronomy

• Walter Baade and Fritz Zwicky invent the concept of neutron star, a new type of celestial object. They suggest that supernovae might be created by the collapse of a normal star to form a neutron star.

Births

• January 6 - Oleg Makarov (d. 2003), cosmonaut
• September 10 - Yevgeny Khrunov (d. 2000), cosmonaut

Deaths

• September 25 - Paul Ehrenfest (b. 1880), Austrian physicist and mathematician.