A helicopter was dispatched to fly him to the Royal Children’s Hospital in Melbourne.
A hospital spokeswoman said the boy remained in a critical condition on Saturday night.
Victoria Police spokeswoman Amelia Penhall said investigators were interviewing the driver of the car that struck the boy.
“The driver and passenger of the car are assisting police with inquiries,” Ms Penhall said.
“Police are also reviewing CCTV footage and speaking to witnesses.”