He was born in Aberdeen, Scotland, around 1823, the son of James Fillans.
He married Helen Simpson, daughter of Thomas Simpson, in May 1853 in New Malton, Yorkshire. They had ? known children:
He was a member of the Invitation Lodge 1081 of the Independent Order of Oddfellows (M.U.).
In 1880, he was appointed to the Central Wards Committee and remained in that post until stepping down in 1882. He was also the president of the East and South Wards Working Men's Association for a period of time in the 1880s.
In December 1880, a notice appeared in the Huddersfield Chronicle stating that Fillans had been given notice to quit his shop on Market Walk by his landlord and that he was therefore offering his stock up for sale. However, it would seem this was resolved as he continued to trade from the address.
By 1891, he had retired to 2 Broad Tenter with his wife. The Census records that their son Archibald was still living with them, along with their niece, Marion Simpson of Malton.
William Fillans died on 14 January 1902, leaving an estate worth £3,674 to his widow Helen. She died in 1909, aged 74.
His son William was the first chairman of the Rugby League Council and, for 30 years, a vice-president of the Huddersfield Cricket and Athletic Club. He was also a chairman of the Yorkshire County Rugby League Committee and a President of the Huddersfield Swimming Association. He remained the head of Fillian and Sons until his death on 13 November 1933, aged 68.
A number of newspaper articles state that William Fillans enjoyed drinking and this occasionally resulted in charges of assault.
A charge was brought again him in May 1856 by Alexander Steward, the latter claiming that Fillans had crushed his hat so much that "it was [now] not worth a penny." The pair had left the George and Dragon Inn on Manchester Street when one of them started a play fight which resulted in them both rolling around on the floor. Steward's witness, John Lorimer, ultimately failed to support to accusation and stated that "he was no violence on either side" and that the pair "had drunk too much of the 'good ale' sold at the George and Dragon, and were both under the influence of the jolly god when the affray too place." The case was dimissed.
In May 1857, he was brought before the local magistrates on a charge of assaulting William Hulke, a reporter for the Halifax Guardian. Apparently one evening Fillans had been drinking at the Bull and Mouth when his wife Helen entered carrying one of their children. Jokingly, Fillians announced the child was for sale and then that his wife was also for sale. His friends made an offer of 5 shillings child and another of "twa-and-saxpence" for Helen. The incident was reported by Hulke in the Halifax Guardian under the headline "A Child Sold by its Father" in which he referred to "Scotty ... a well known working Jeweller 'Frae the North'" in disarranging terms.
Although the article didn't name Fillans, he felt it was libellous and an altercation subsequently took place. As he walked away, he heard Hulke shout out "Go home and sell thy wife and child." Hulke then claimed that Fillians assaulted him in "an attempt to curtail the liberty of the press", which resulted in his shirt being torn. However, witnesses stated that no assault took place and that what was torn was a piece of paper being carried by Hulke. After adjourning for a week to hear from further witnesses after which the bench dismissed the case as unproven.
In October 1863, he assaulted Lewis Ludwig, a fellow jeweller of Cross Church Street. It was stated that Fillans was "the worse for liquor" and had grabbed Ludwig and struck his head against a bookcase, "rendering him partially insensible." Fillans failed to appear before the magistrates, was found guilty and fined 20 shillings plus costs in his absence.
In 1866, he met his match when attempted to assault Mr. W. R. Croft of Rashcliffe. It was reported that Fillans threw the first punch, but that Croft had "thereupon thrashed him." Inspector White had been passing by and broke up the fight. The case was withdrawn.
In July 1870, he was found guilty of being drunk in King Street. Councillor H. Hirst stated that Fillans "had been in the habit of insulting him every time he had met him for the last four years." On this particular occasion, Fillans had followed Hirst down the street, calling him a "thief" and a "murderer". Hirst stated that this only happened when Fillans had been drinking — "He has never said anything to me when sober, but I assure you he is oftener drunk than sober."
In September 1871, William's sister Annie, who had married Thomas Simpson but then left him to live "with a man named Styring", assaulted Helen Fillians in John William Street. It was claimed that Annie had punched Helen in face, "rendering her insensible for a short time", and then grabbed her around the neck. When challenged, Annie reportedly said, "I have often said I would give it to thee, and I will give it thee right now!" before Police Constable Salmon intervened. In court, Annie claimed that she had not struck the first blow and that Helen and three others had beaten her first. The magistrates fined Annie a total of £3 4s. 6d. and warned against assaulting Helen again.
In November 1884, he was fined 20 shillings plus costs of £1 1s. for assaulting Alderman Joseph Woodhead, the proprietor of the Huddersfield Examiner. The assault took place during "an excited meeting held in connection with the recent municipal elections" and it was stated Fillans "stuck Mr. Woodhead, and knocked him off a wall which was [being] used as a platform", after allegedly shouting out "Take that, you bastard!" Fillans, who had also climbed up onto the wall, then fell (or was pushed) off. Perhaps aware of Fillan's prior history, the magistrates who heard the subsequent case asked if he'd been drunk, but a witness responded, "I did not notice that he was beerified."