William Hayward Wakefield (1801 - 19 September 1848) was an English colonel, the leader of the first colonising expedition to New Zealand and one of the founders of Wellington. In 1826, he married Emily Sidney, a daughter of Sir John Sidney.
Born just outside London, he was largely raised by his elder sister, Catherine, who found him a difficult child. As he grew older he came very much under the influence of his older brother, Edward Gibbon Wakefield, who was not always a good influence on his life.
In 1825 he became formally betrothed to Emily Sidney but, before they could be married, Wakefield became involved with his brother in the abduction of a wealthy heiress and both brothers were arrested. Then, while out on bail, Wakefield absconded to Paris, apparently to meet up with Emily who by now was three months pregnant. He returned to England when the baby was born and was promptly arrested and held in Lancaster Castle until his trial. He was subsequently sentenced to three years in jail. During this time his 'wife' died leaving him with a six-month-old daughter, Emily.
Upon his release from jail, Wakefield spent some time with his daughter at his sister Catherine's. Then in 1832 he travelled to Portugal and enlisted as a mercenary soldier in the service of Dom Pedro, the Emperor of Brazil. Although he had no military experience whatsoever he was apparently able to enlist as a Captain. He survived the siege of Oporto and the subsequent campaigning, but he gained little from it except experience and a handful of medals.
After the Portuguese Campaign he returned briefly to England and enlisted in the British Auxiliary Legion fighting for the infant Queen Isabella II of Spain in the First Carlist War. He emerged from the campaign as a major, re-enlisted and was promoted to Colonel. Among his junior officers was Henry Inman (police commander). Wakefield was one of the few officers to survive the campaigns of the following years; he stayed until the Legion was disbanded in 1837 and returned to England the following year.