Michael Charles Grant, 12th Baron de Longueuil (born 1947) is a nobleman possessing the only French colonial title recognized by the Monarch of Canada, currently his third cousin, Charles III.

He assumed the title of Baron de Longueuil in 2004 upon the death of his father, Raymond Grant, in Navarrenx, near Pau, France.

A medical practitioner, Grant de Longueuil has interests in palliative medicine, working for 13 years at Hayward House.

Grant de Longueuil married Isabel Padua,[1] born in the Philippines and of mixed Spanish and Filipino origin.

The Kingston home of the barons, Alwington House, was sold out of the family in 1910.