The incident happened outside Billingshurst Primary School near Horsham yesterday, according to headteacher Helen Williamson.
She said: “He was hit by a car yesterday [September 12]. Police are investigating.”
In a statement on the school’s Twitter account a spokesman added: “Just to let you all know that John, our crossing patrol is home and ok.
“He has broken ribs and is rather bruised. We all send him our love and wishes for a speedy recovery.”
The spokesman urged drivers to take ‘great care’ around the school and to follow safety advice.
Sussex Police and West Sussex County Council have been approached for comment.