The Leica M1 is a 35 mm camera by Leica Camera AG, introduced in 1959. The M1 has no rangefinder, but a parallax-corrected viewfinder with frames for 35 and 50mm permanently displayed. 9431 were made.
The M1 was the cheapest and simplest Leica M body. As such, it was suitable either as a low-budget general purpose camera, or as an interface to other instruments, like the Visoflex, or scientific instruments (telescopes, microscopes, etc.).
Several similar models were made in parallel with later iterations of the Leica M family: