Police said the 16-month-old baby, who was outside a cafe at Central Railway Station on Thursday morning, suffered a cut to the face.
After the assault, the attacker ran away towards Elizabeth Street with the child's father chasing him, officers said.
A 28-year-old man has been charged with assault occasioning actual bodily harm.
He will appear at Central Local Court on Friday.
Australian police have charged a man accused of punching a baby girl in her pram at a railway station in Sydney.