Sir William Magnay, 2nd Baronet (1855 – 8 January 1917) was an English baronet and novelist.
Magnay was a son of Sir William Magnay, 1st Baronet who was Lord Mayor of London. He succeeded to the baronetcy in 1871. He was a prolific novelist, and published twenty-five novels before his death; a further three were brought out posthumously.
Magnay married in 1879, and was himself succeeded by his son Christopher Magnay, born 1884.
Magnay's publications included:
| Escutcheon: | Ermine fretty Gules on a chief per pale of the second and Azure a sword Proper pommel and hilt Or surmounting a key saltirewise the ward upwards Gold interlaced with the collar of the Lord Mayor of the City of London between two leopards' faces Erminois. |
| Crest: | A lion rampant Sable billety Erminois murally crowned gorged with a chain reflexed over the back and holding between the forepaws a leopard's face Or. |
| Motto: | Magna Est Veritas[1] |