William Watts (1722 – 4 August 1764) was chief of the Kasimbazar (or Cossimbazar) factory of the British East India Company. He lived in Bengal, and he was proficient in Bengali, Hindustani and Persian languages.
Robert Clive engaged him to work out a secret plan for the final overthrow of Siraj Ud Daulah and to install a favourable Nawab on the masnad. Watts thus set up contact with the dissident amirs of the Murshidabad durbar including Mir Jafar, Rai Durlabh and Yar Lutuf Khan. William Watts played a role in forging the grand conspiracy against Siraj Ud Daulah which led to his final overthrow at the Battle of Plassey. On 5 June 1757 he personally visited Mir Jafar and obtained his oath of allegiance.
In recognition of his services he was given £114,000 from the Nawab's treasury and made the governor of Fort William on 22 June 1758, in place of Roger Drake who had deserted the fort when it was attacked and captured in June 1756. This had been the location of the Black Hole of Calcutta on 20 June 1756.
Four days later he resigned in favour of Robert Clive to return to England.
He wrote a book Memoirs of the Revolution in Bengal which was published in 1764.
William is buried in the Watt vault in Hanslope church.
William was born in 1722 in Glasgow, Scotland.
On 24 March 1749 William married Frances Altham, née Croke (10 April  1728 – 3 February 1812) in Calcutta, the twice-widowed second daughter of Edward Croke or Crook (1690 – 12 Feb 1769) the Governor of Fort St. David, 100 miles south of Madras and Isabella Beizor a Portuguese Indian Creole.
Watt died August 1764, leaving three surviving children (one child, William, died in infancy).
When William Watts died in 1764, Frances returned to India to settle his estate. Although a wealthy young widow aged 36, it was ten years before she married William Johnson in 1774, a chaplain of the Presidency of Fort William. Frances became known as the 'Begum' Johnson[according to whom?].
By 1787, the Johnson marriage was declared at an end, and Frances offered William a settlement and an annuity, with which he returned to England. Frances was 59 years old and never married again.
She died in Calcutta on 3 February 1812. Her memorial in St Johns Church, Calcutta  states 'The oldest British resident in Bengal, universally beloved, respected and revered'.
- Begum Johnson's memorial at St. John's Church, Calcutta. This was Frances' third marriage. She had first married in 1738, in her thirteenth year, one Parry Purpler Templer who died five years later; both their children died young. She then married 2ndly James Altham, who died shortly after their wedding circa 1747. She remained a widow for two years, and then married William Watt, aged about 23/24. Frances would be known to history as Begum Johnson, by the name of her last husband, Rev William Johnson, principal chaplain of Fort William, whom she married in 1774, ten years after the death of her third husband. For a fuller biography, which details her career in 1756, when she and her husband were honorably treated by the Nawab of Bengal. Mrs Watts returned to India around 1769, possibly because she didn't feel comfortable in England, having grown up in warmer India, and ostensibly to settle her late husband's tangled business affairs.
- Hanslope and District Historical Society
- Grave of Begum Francis Johnson, at St. John's Church complex, Calcutta
- Memoirs of the Revolution in Bengal From the Collections at the Library of Congress