A compound microscope is a microscope with more than one lens. Compound microscopes are used in particular to view transparent items or items cut into slices thin enough to be transparent.

It was claimed to be invented in 1590 by Hans Janssen and his son Zacharias Janssen, but this is disputed. Galileo Galilei developed it under the name occhiolino in 1609, and later in 1612 presented it to Polish king Sigismund III.