The toddler, who was visiting the Island from the UK, was hit by a car near the Millennium Town Park at around 3.50 pm.
States police officers, forensic specialists and paramedics attended the scene of the accident in Tunnell Street and the road was closed for around four hours.
A 38-year-old female driver was arrested following the incident but has since been released on police bail.
In a brief statement released on Tuesday morning the States police said: ‘The three-year-old boy who was injured in yesterday’s road traffic collision at the Town Park has been transferred to Southampton Hospital where he remains in a critical condition.
‘A 38-year-old woman was arrested yesterday for offences under the Road Traffic Law. She has been released on bail.’
