Emergency services were to reports of the child walking on the hard shoulder near Brasted just after 12pm on April 7.
It is believed he made his way onto the busy road from a nearby property.
He was spotted by a member of the public who then helped him back to safety where he was offered professional safety advice by police.
Patrol officers also conducted a series of welfare checks on the boy after visiting his house and speaking to his family.
A spokesperson for Kent Police said: “Kent Police was called at 12.07pm on April 7, 2025 to concerns for the welfare of a young child seen on the hard shoulder of the M25 near Brasted.
“A member of public assisted the child who was reported to have gained access to the hard shoulder from a nearby property.
“Patrols visited the property and spoke to the child’s family who had also been searching for him.
“Welfare checks were made and safety advice was provided.”
