The man was cut free from his vehicle by firefighters.
The horse was killed in the incident.
It is understood the animal escaped from a nearby field.
The owner was at the scene shortly after the collision, which happened on the A71 in Overtown, near Wishaw, Lanarkshire.
The injured man was trapped in his vehicle as a result of the collision at about 9.50pm on Tuesday.
Firefighters had to use special cutting equipment to release the driver from his vehicle following the incident.
The road had to be closed.