Diego Grabowski was playing on his scooter near to his home in Cottingley when he noticed the two-year-old boy wandering about on his own.
The child had managed to get out of the back garden of his home further up the road by unwinding a bike lock that was securing the gate and squeezing through the gap while his mother was momentarily distracted seeing to her baby.
Minutes later when she realised her son wasn't in the house, she immediately called police and the boy's father began a frantic search of the area.
Meanwhile, Diego had realised the boy should not have been out alone and led him to the nearest adult, which was a man working in a garden nearby.
They then came across the boy's father out looking for him and he was reunited.
PC Mark Rodgers, a response officer based at Morley Police Station, went to the call and saw how Diego's actions had helped to keep the younger boy safe.
He put him forward for official recognition which saw Diego given the VIP treatment at Leeds District Headquarters in Elland Road, where he was presented with a certificate and given a tour of the station.
Superintendent Derek Hughes, who made the presentation, said: "It's truly heartwarming that someone as young as Diego was able to recognise the risks to the missing boy and take him to safety.
"It showed great presence of mind and he is a credit to his family and fully deserves to be praised for his actions.
"It is very unusual for someone as young as Diego to play such a vital role in bringing an emergency situation like this to a successful conclusion, and he is probably the youngest person we have ever commended.
"We hope his visit to us was enjoyable and was a suitable reward for his quick thinking and public-spirited behaviour. We also hope he will enjoy telling his schoolmates all about it and encouraging them to be good citizens too."