| Age | 74 (age at death) |
| Birthday | 1675 |
| Birthplace | Llanfihangel Tre'r Beirdd, Isle of Anglesey |
| Died | 3 July, 1749 |
| Place of Death | London, England |
| Nationality | Welsh |
| Occupation | Mathematician |
William Jones, FRS (1675 – 1 July 1749) was a Welsh mathematician, most noted for his use of the symbol π (the Greek letter Pi) to represent the ratio of the circumference of a circle to its diameter. He was a close friend of Sir Isaac Newton and Sir Edmund Halley. In November 1711 he became a Fellow of the Royal Society, and was later its vice-president.
