The four-year-old died at his family's farm in Lesmahagow, South Lanarkshire, on Thursday.
A Police Scotland spokeswoman said: "A four-year-old boy has died following an incident involving a horse at his family's farm in Lesmahagow on Thursday, January 2.
"He was taken by ambulance to Wishaw General Hospital but died from his injuries a short time later.
"A post-mortem examination will be held in due course to establish the exact cause of death.
"However, the death is not being treated as suspicious."