The toddler, from Liverpool, landed in a 2ft deep pool after the fall in Wales on Sunday.
The terrifying incident happened at the Pistyll Rhaeadr waterfall in Llanrhaeadr Ym Mochnant, Powys.
An aunt desperately tried to grab the tiny tot as he fell but slid 25 ft down the waterfall with him before a tree branch broke her fall, the Sun reported.
The boy was pulled from the water by a tourist with just a scratch to his face, while a climber rescued the aunt who was stuck in the tree.
Phil Facey who witnessed the horrifying ordeal told newspaper: “I heard the screams and went outside and saw a man bringing the boy out of the water. I thought he was dead, he looked blue."
An air ambulance arrived at the scene within 20 minutes.
“The boy was shocked and quite woozy, so the doctors stayed for about 45 minutes before allowing them to go home. It was a miracle they both survived, they both should have died. I felt like it was something divine," Mr Facey said.
According to witnesses the pair had walked up the side of the waterfall where there is no path.
A Welsh Ambulance Service spokesman told the BBC it was called at about 1pm on Sunday and said a boy was treated at the scene for minor injuries.
The Standard has contacted Welsh Ambulance Service for further comment.
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