Mechanical clocks were invented in the northern hemisphere, the half of the world north of the Equator. Before they existed, people used sundials to tell the time. In a sundial, it is the shadow cast by the bit in the centre that actually indicates the time of day. In the northern hemisphere, this moves in what we now call a clockwise direction. So when the first mechanical clocks were invented, their faces and hands were built to follow the same direction.
If clocks had been invented in the southern hemisphere, everything would have been reversed. The shadow on the sundial mover in the opposite direction, and presumably clocks would have been built to run that way too.