Sir John Sparrow David Thompson PC KCMG QC (November 10, 1845 – December 12, 1894) was a Canadian lawyer, judge and politician who served as the fourth prime minister of Canada from 1892 until his death.

Annie Thompson was strong-willed and had the same kind of spirit that had driven Agnes Macdonald (another prime minister's wife) to ride the cowcatcher of a Canadian Pacific Railway train through the British Columbia mountains.

Thompson was called to the Nova Scotia Bar in July 1865, and from 1878 to 1882, he served as Attorney General in the provincial government of Simon H. Holmes.

After his resignation from government, Thompson was immediately appointed to the Nova Scotia Supreme Court by the Prime Minister Macdonald.

The speech was notable and helped to popularize Thompson, and he quickly rose to become a leading member of the Conservative government.

After 1893 Prince Edward Island House of Assembly passage of the amalgamation "Bill respecting the Legislature," Thompson, still wary of a Protestant backlash, reported to the Canadian Governor General that almost every article of the Prince Edward Island "amalgamation" statute, save for a punitive clause that violated with "little injury" the separation of powers between the Legislative Assembly and provincial court system, was "unobjectionable, and may be left to their operation."

Then, in a demonstration that his tenure as Prime Minister would not result in a papal majority government, Thompson disregarded Conservative allegations of gerrymandering of French Acadian and otherwise Roman Catholic voters in Prince Edward Island.

His first major speech as Prime Minister was given in Toronto in January 1893 and covered the topics of tolerance and Canadian nationalism in conjunction with loyalty to the British crown.

Despite his concern, Thompson ultimately realized that the conspiracy to make Canada part of the United States was confined to a small and noisy minority within the opposition party.

In March 1893, Thompson travelled to Paris as one of the judges on the tribunal to settle the dispute over the seal harvest in the Bering Sea.

[6][7] Thompson's physical condition had deteriorated during his time in Ottawa; he was significantly overweight when he died (standing 5 feet 7 inches (1.70 m), he weighed about 225 pounds (102 kg)), and had always pushed himself very hard in his work.

(Three retired prime ministers died out of Canada: Charles Tupper, Richard Bedford Bennett, and Brian Mulroney).

After an elaborate funeral was staged for him in the United Kingdom by Queen Victoria, Thompson's remains were transported back to Canada aboard the armoured cruiser HMS Blenheim, which was painted black for the occasion.

[4][8] Despite having held prime ministerial office, Thompson had little estate, so Parliament set up a fund to support his widow and children.

After she was widowed on December 12, 1894, a fund of $30,000 was raised for Lady Thompson, headed by Lord Strathcona with a subscription of $5,000; the Parliament of Canada contributed $25,000.

[13] He was identified as "The great "might-have-been" of Canadian Prime Ministers...", whose potentially promising career was cut short by his early death.

Since 1996, Sir John Thompson's former home in Ottawa at 237 Metcalfe Street has served as the national office of the Canadian Soccer Association.