The Carnegie Grant of for the Whitby Public Library came to $10,000. The architect was William Austin Mahoney, who designed 16 other Carnegie libraries in Ontario, and the contractor was James Brogue. On June 9, 1913 the cornerstone was laid with a silver trowel which is now on display in the Archives and Local History Gallery at the Central Library. Library Board member Arthur Allin placed coins and copies of local newspapers under the cornerstone.
On May 1, 1914, Colonel John Farwell, Clerk of Ontario County, officially opened the Carnegie Library before 100 invited guests. The new Whitby Public Library was designed in the Beaux-Arts architectural style with a grand exterior staircase leading up to a large main entrance. Large columns, a triangular centre gable, and large windows on either side of the entrance made for a very grand building. Inside, the library housed separate reading rooms for men, women, and children and 8 book stacks containing 5000 volumes.