Lieutenant-Colonel Henry James Grasett, CMG, (June 18, 1847 — September 30, 1930) was a Canadian army and militia officer and Toronto police chief. He is the longest-serving police chief in the history of the Toronto Police having served for 34 years from 1886 to 1920 as Chief Constable. Grasett served as vice-president of the International Association of Chiefs of Police in 1902 and as president of the Chief Constables' Association of Canada in 1906. Grasett retired as chief constable in 1920, at the age of 73. He died of pneumonia at his home in 1930 and was buried in St James' Cemetery.