Born as William Smijth, he was the oldest son of Sir Edward Bowyer-Smijth, 10th Baronet and his wife Laetitia Cecily Weyland, daughter of John Weyland. On 10 June 1839, his name was changed to Bowyer-Smijth by royal licence. He was educated at Eton College and went then to Trinity College, Cambridge. In 1850, Bowyer-Smijth succeeded his father as baronet.
From 1845, he played for the Marylebone Cricket Club until 1848. Bowyer-Smijth contested South Essex in the 1847 general election unsuccessfully. He entered the British House of Commons in 1852, sitting as a member of parliament (MP) for until 1857. Bowyer-Smijth had a commission as lieutenant in the 19th Essex Rifle Volunteers and served as a Deputy Lieutenant and a Justice of the Peace.
On 2 April 1839 he married firstly Marianne Frances Meux, second daughter of Sir Henry Meux, 1st Baronet in Cheshunt in Hertfordshire and had by her two sons and a daughter. Bowyer-Smijth later left his wife and pretending to be a widower, he began to court Eliza Fechnie Malcolm, daughter of David Baird Malcolm, who was aged sixteen at that time. Under the impression of a feigned ceremony, she considered herself to be lawful married and borne him twelve children, six sons and seven daughters until 1873, when she learned that his wife was still alive. When he promised to make up the marriage after the death of Marianne, she however continued to stay with him.
Bowyer-Smijth's first wife died on 19 March 1875 and he remarried Eliza in Cheltenham in London only a week later. Only two daughters born after the marriage, were legitimately, all others illegitimately. Although legitimised under Scottish law by petition in 1918, the English baronetcy and estates could not pass to these children. Bowyer-Smijth died, aged 69 in Twineham Court in Sussex and was succeeded as baronet by his oldest son William of his first marriage, after whose death the title went to his nephew Alfred Bowyer-Smyth. Eliza survived her husband until 1926.
- "Leigh Rayment – Baronetage". Retrieved 9 November 2009.
- Dod, Robert P. (1860). The Peerage, Baronetage and Knightage of Great Britain and Ireland. London: Whitaker and Co. p. 513.
- "No. 19743". The London Gazette. 18 June 1839. p. 1207.
- "Smyth (or Bowyer-Smijth), William (SMT831W2)". A Cambridge Alumni Database. University of Cambridge.
- Dod, Robert P. (1856). The Parliamentary Companion for 1856. London: Whitaker and Co. p. 269.
- "ESPN, cricinfo – William Bowyer-Smijth". Retrieved 9 November 2009.
- "Leigh Rayment – British House of Commons, Essex South". Retrieved 9 November 2009.
- T. L. Behan, ed. (1865). Bulletins and Other State Intelligence for the Year 1861. vol. II. London: Harrison and Sons. p. 1768.
- "ThePeerage – Sir William Bowyer-Smijth, 11th Bt". Retrieved 24 December 2006.
- Scots Law Times. vol. I. Edinburgh: W. Green and Son. 1918. p. 156.
- "A Legitimacy Claim". The Argus, Melbourne. 7 December 1917. p. 7. Retrieved 9 November 2009.
- Fox-Davies, Arthur Charles (1895). Armorial families. Edinburgh: Grange Publishing Works. p. 119.
- Hansard 1803–2005: contributions in Parliament by Sir William Bowyer-Smijth, 11th Baronet
|Parliament of the United Kingdom|
Sir Edward North Buxton
Thomas William Bramston
|Member of Parliament for South Essex
With: Thomas William Bramston
Thomas William Bramston
|Baronetage of England|
(of Hill Hall)