William Blackall was born in Middlesborough, England. He was educated at Hertford Grammar School and received his bachelor of arts degree from the University of London in 1890. He came to Newfoundland as headmaster of Bishop Feild College in 1891.

In 1898 he helped organize the Newfoundland Teachers’ Association and was the association’s president until 1899. In 1908 he became the Church of England’s superintendent of Education and travelled around the island on long tours of inspection. He also helped form the Newfoundland Amateur Athletic Association and was its first president.

As early as 1913, Blackall began travelling to the Maritime provinces to negotiate academic co-operation with universities there. These discussions established academic standards and helped pave the way for the first generation of Memorial University College graduates who would complete the final years of their degrees in Nova Scotia and New Brunswick.

Blackall often worked in close collaboration with Levi Curtis and Vincent Burke. So much so, in fact, they referred to themselves humorously as "the three musketeers."

A bronze bust of William Blackall is on display in the lobby of the Arts and Administration Building, St. John's campus. Blackall House, in Paton College, is named in his honour.