The Carol Bateman School of Dance, http://www.cbsdhk.com/ does ballet lessons for toddlers.
Carol Bateman School of Dancing
The Helena May, 35 Garden Road, Central.
Tel: 2525 3751 Fax: 2525 3798
(They also have a school in Kowloon and in Shatin.)
Their ?Babies? class is for three year olds to five year olds but my younger daughter started in this class when she was two (before they started the toddler classes).
Her big sister was already having lessons at Carol Bateman and she was desperate to have them too.