Waldo (1940) is a novella by Robert A. Heinlein originally published in Astounding Magazine. It is also available in the book Waldo & Magic, Inc..

A crippled genius named Waldo lives in an orbital habitat and works earthside via remote manipulators he developed. They were described as having the shape and dexterity of a human hand, thus allowing it to handle any human tool. They were available in a variety of sizes, from micro-manipulators to construction sized.

In the modern sense, a waldo is a remote manipulator. Modern waldoes may have direct mechanical linkages or be teleoperated as the originals in the story were. They may also be expanded to include almost any part or function of the body.

See also: Virtual reality, Telepresence, Cyborg.