The 32-year-old waited for the driver to enter the store in Shepparton, in rural Victoria, before jumping into the red Volkswagen with the 15-month-old sleeping inside, police say.
CCTV footage shows the man stopping the car after discovering the sleeping baby just after 2pm on November 14.
He was captured on camera picking up the baby before placing it in a box in the car park.
The female victim returned and found the child, who was not physically injured, before raising the alarm.
The stolen car was found the next day in the nearby town of Mooroopna.
Police arrested the alleged offender in central Shepparton on Friday afternoon.
The Mooroopna man has been charged with the theft of a motor vehicle, reckless conduct endangering serious injury and committing an indictable offence while on bail.
Detectives also charged the man with multiple offences over an unrelated incident in the Shepparton and Barmah areas on November 17.
The charges include the theft of a motor vehicle, dangerous driving while pursued by police and aggravated reckless exposure of a police officer to risk by driving.
He has been remanded to appear at Shepparton Magistrates' Court on Monday.