Sparks was born in County Wexford in Ireland and came to Canada in 1816. He was recruited by Ruggles Wright (or by other accounts Ruggles' brother Alonzo) at age twenty-four to voyage to Canada as a labourer in the Wright family's massive logging and farming enterprises in the location of modern Gatineau.
After saving his labourer's salary for several years Sparks purchased 200 acres (0.8 km²) on the Ontario side of the Ottawa River in 1823. This land covered much of what is today downtown Ottawa stretching from what is today Wellington Street in the north almost to Somerset in the south (or only to Laurier Avenue according to other sources). It stretched west to modern Bronson Avenue and extended eastwards further than the Rideau Canal into what is today Sandy Hill.
In 1823, Sparks married Sarah Wright, the widow of one of Ruggles Wright's brothers. He adopted Sarah's nine children.
The building of the final section of the canal saw the government expropriate the eastern section of his land, taking everything east of modern Elgin Street (then known as Biddy's Lane). While losing some of his land, this proved a great benefit for Sparks as the location of the canal greatly increased the value of his other holdings.
Sparks set out to encourage the establishment of commercial ventures on his property, which had proven to be poor farmland. Thus he established a market and donated land for civic buildings. Ottawa's first church was built on a piece of his land at the corner of what is today Laurier Avenue and Chapel Street.
He also donated land to the Church of Scotland, on which was built St. Andrew's Presbyterian Church, and for a new court house and fire station. When his West Ward Market, unable to compete with Lower Town's Byward Market, failed he donated the building to become Bytown's first city hall. In 1832, he donated some land at the northwest corner of his property to the Anglican Church and that is still the site of Ottawa's Christ Church Cathedral.
While Ottawa remained a small town and commerce centred somewhat to the north of Sparks' holdings he did become a wealthy and important city figure. In 1827, the government had seized some of Sparks' holdings intending to construct a fortress to defend the new canal. Sparks challenged this appropriation of the land that would later hold Canada's parliament buildings. He succeeded and was awarded a fortune of 27,000 pounds for the land that had become built up in the intervening years. With this money he invested in enterprises across the region, and became an important financier.
Around 1848, he had a street carved through the centre of his holdings; this would later be known as Sparks Street, one of Ottawa's central commercial areas.
In 1847, he became a member of Bytown's first city council. When the new city of Ottawa was created to replace Bytown in 1855, Sparks also served on its council until 1860.
The selection of Ottawa as the capital of Upper and Lower Canada in 1857 further enhanced the value of Sparks' land and made him even wealthier.
Sparks' wealthy descendants continued to be prominent citizens in Ottawa for many generations, the most prominent being Percy Sparks who spearheaded the creation of Gatineau Park. Today there are many Sparkses living in Ottawa.