Duncan David Hay was born in 1868 in Listowel, Ontario the fifth child of David Davidson Hay and his wife Janet Rogerson.
Duncan’s father, David, must have been an adventurous young man as he left Scotland on his own at age 17. He travelled first to Bowmanville and later to Innisfil, Simcoe County. In Innisfil he met and married Janet Rogerson in 1851. Janet had also been born in Scotland and emigrated with her family. They were joined by David’s parents and siblings who had left Scotland a few years after he did. The family moved on to Elma Township to settle into farming in the neighbourhood which later became part of Listowel. Listowel officially became a village in 1867 and David Davidson Hay was the first reeve from 1867 to 1872.
David Hay left farming to become the North Perth County Registrar. As such, he moved his family to Stratford where the registry office seems to have been a family affair. According to the 1889 City Directory; David was the registrar, his sons Duncan and Warren were both deputy registrar and his sisters Lillie and Nellie were copyists in the registry office.
In 1895, 27 year old Duncan married 29 year old Emma Down. She was the daughter of William Down and Elizabeth Larkworthy. In 1867 William had been an importer and dealer in groceries, provisions, fruit and oysters as set out in an ad in the directory of that year. He later became the city commissioner. Emma’s mother, Elizabeth Larkworthy, was the daughter of Orange and George Larkworthy who was a butcher and the first Stratford town constable.
Duncan and Emma moved into the newly built house at 84 Mornington in 1905. Duncan who was Deputy Registrar at that time became the registrar upon his father’s death in 1908. Duncan was an enthusiastic curler and bowler and all round sportsman. Around 1910, he joined Robert Frame to form the Frame and Hay Fence Co. of which he was the secretary-treasurer.
The Hays, who had no children, left Stratford in 1912 and made Winnipeg their home for a few years.
They returned to Stratford in 1915 when Duncan was very ill. He died in 1917 at the age of 49. His pall bearers included his longtime friend and neighbour Charles E Nasmyth. Emma Hay moved to 39 Elizabeth Street.  She died June 11, 1952 at the age of 86 years and was buried beside her husband in Avondale Cemetery.