| Sir William Coates | |
| Office: | Lord Mayor of Belfast |
| Term Start: | 1929 |
| Term End: | 1931 |
| Predecessor: | William George Turner |
| Successor: | Crawford McCullagh |
| Term Start1: | 1920 |
| Term End1: | 1923 |
| Predecessor1: | John C. White |
| Successor1: | William George Turner |
| Office2: | High Sheriff of Belfast |
| Term Start2: | 1906 |
| Term End2: | 1907 |
| Predecessor2: | Henry O'Neill |
| Successor2: | Peter O'Connell |
| Birth Name: | William Frederick Coates |
| Birth Date: | 1866 |
| Birth Place: | Belfast, Ireland |
| Education: | Royal Belfast Academical Institution |
| Spouse: | Elsie Millicent Gregory |
| Occupation: | Stockbroker |
Sir William Frederick Coates, 1st Baronet, (1866 – 19 January 1932) was an Irish stockbroker and politician in Belfast.
Coates was born in Belfast in 1866. He studied at the Royal Belfast Academical Institution.[1] He was the son of David Lindsay Coates and Sara (née Mulligan) Coates.[2]
He initially entered the linen trade, but became a stockbroker in 1887, building up an extensive business known as William F. Coates & Co, stockbrokers. In 1902 he was elected to Belfast Corporation. He was chairman of the finance committee from 1917 and was elected Lord Mayor of Belfast in 1920 and then re-elected twice, serving until 1923.
He hosted the King and Queen when they visited Belfast to open the Parliament of Northern Ireland (of which he was also a Senator, both ex officio as Lord Mayor and as an elected member 1924-1929[3]) in July 1921. For hosting the monarchs, and guiding Belfast past the sectarian conflict that marked the creation of Northern Ireland in the early 1920s, Coates was created a Baronet of Haypark. He served as Lord Mayor again from 1929 to 1931.
He served as High Sheriff of Belfast (1906–1907) and as High Sheriff of Antrim (1931–1932).
On 27 November 1907, Coates married Elsie Millicent Gregory, daughter of Colonel Frederick William Gregory. Together, they were the parents of:[2]
Coates died on 19 January 1932 and was succeeded by his son Frederick.[4] Upon his son's death in 1994, Sir William's grandson, David Frederick Charlton Coates (b. 1948), became the 3rd Baronet.[2]
| Notes: | Granted 20 June 1923 by Sir Nevile Rodwell Wilkinson, Ulster King of Arms.[5] |
| Escutcheon: | Gules a chevron cotised Argent on a chief Ermine two bells Or on an escutcheon of pretence quarterly 1st & 4th Argent a fir tree growing out of a mount in base Vert surmounted by a sword in bend supporting an Imperial crown in the dexter canton Proper and in chief and base a lion's head erased Azure 2nd & 3rd Gules three bears' heads couped Argent muzzled Sable. |
| Crest: | On a wreath of the colours a cock statant wings closed Gules. |
| Mantling: | Gyles doubled Argent. |
| Motto: | Watchful And Bold |