Edward Shillington was born in Belfast, Ireland, and baptised there on 15 March 1835. He was the son of Margaret Little and her husband, Edward Shillington, a labourer. Little is known of his early life, but he spent 21 years with the Royal Engineers. On 19 January 1856 he married Fanny Gallagher in Belfast. After her death he married a widow, Clara Gillespie (née Corney), at Alverstoke, Hampshire, England, on 6 February 1865.
After a period of military service in China, Shillington arrived in New Zealand in mid 1880 with his wife. The Auckland Free Public Library was due to open on 7 September in that year in the former entertainment hall of the Auckland Mechanics' Institute, whose own library had provided reading and reference facilities for the city since 1842. Shillington applied for the advertised position of first librarian. Of the 42 applicants for the post, few, so far as was known, had mixed much with books. The decision was finally made to appoint 'a married man' for no better reason, it seemed to the New Zealand Herald, than the fact that with the cessation of Sir Julius Vogel's immigration scheme, 'those who incurred the responsibilities of matrimony should be encouraged.' Shillington's remuneration was about that of the city turncock, whose work it was to switch on and off water for the mains.
As librarian Shillington had nominal charge of the collections, but was not expected to take part in their selection. That task was entrusted to a committee of academics, senior journalists and businessmen. His successor remembered him as 'a typical military man' whose aim it was to see that visitors obeyed the rules, of which there were many. In his first year he was able to report that more cakes of soap had disappeared from the public washroom than books from the shelves (two only were unaccounted for); he had had occasion to speak only twice in 12 months to 'gentlemen' for spitting on the floor. And, as an example of what he termed 'biblio-kleptomania', a would-be thief whom he personally apprehended in 1892 was sentenced to three years' penal servitude.
The opening of a new library building – now the Auckland City Art Gallery – on 26 March 1887 brought Shillington a new-found prominence in the community, and a personal friend in Sir George Grey, the library's greatest benefactor. In collaboration with Grey, he was responsible for receiving and arranging on the shelves Grey's wide-ranging and important collection of books and manuscripts in both English and Maori, as well as his collection of pre-1501 printings. Shillington was also director of the city's art gallery after its opening in the same building in 1888.
In 1890 Shillington requested an increase in salary. Although still allowed only limited participation in book selection, he now had added responsibilities: the new library was much larger than the old one, and he no longer had a clerical assistant. The request was refused, the council's minutes noting 'the desirability of obtaining a librarian with a good literary knowledge'. Such an appointment would not come about for a further 23 years. Shillington was retired in 1913 and appointed one of two curators of the Grey collection. He died in Auckland on 28 July 1920, survived by his wife, and a son and daughter of his first marriage.