The Letov Š-4 was a Czechoslovak single-bay, unstaggered biplane fighter and trainer in the 1920s.

It first flew in 1922, with fabric-covered wooden wings and a metal fuselage and tail.

The Czechoslovak Air Force ordered 20 Š-4s in 1922 and these were delivered in early 1923.

The plane lived out the 1920s as a fighter and trainer, but by 1927 difficulties were being experienced due to the low manufacturing quality of the Š-4.

Data from Jane's all the World's Aircraft 1924[1]General characteristics Performance Armament