James Delamere Lafferty (April 28, 1849 – July 29, 1920) was a Canadian physician and politician. He served one term as the fifth mayor of the town of Calgary, Alberta from January 20, 1890 to January 19, 1891.
Lafferty was born in Perth, Ontario in 1849 and attended local schools. He then worked as deputy registrar of titles in Kingston to finance his further education. He graduated from Queen's University medical school in 1871. Lafferty practised medicine for a year in Perth before becoming a senior resident at Ward Island hospital (later Bellevue Hospital) in New York City and at the New York Eye and Ear Infirmary. Lafferty next took a post-graduate course at St Bartholomew's Hospital in London, England.
In 1873, he set up practice in Pembroke, Ontario; later that same year, he married Jessie P. Grant. From 1877 to 1880, Lafferty also operated a drug store in Pembroke. In 1880, he was named associate coroner for Renfrew County. The following year, Lafferty was offered the position of chief surgeon for the eastern division of the Canadian Pacific Railway (CPR) and moved to Winnipeg, Manitoba later that year. Lafferty and his family had moved to Regina, Saskatchewan by 1885 and then moved on to Calgary in December 1885.
In Calgary, Lafferty took on the contracts to provide medical services for the CPR mainline and for the nearby Indian reservation. In 1889, he was a founding member of the North West Territories Medical Association and, in the following year, was elected to the medical council for the College of Physicians and Surgeons of the North West Territories. He served on the council until 1906, also serving three terms as president. In 1901, he became medical registrar for the North West Territories. When the provinces of Alberta and Saskatchewan were formed, Lafferty drafted the Medical Profession Acts for both provinces. In 1906, he organized the meeting which formed the Alberta Medical Association. Later that same year, he organized the first meeting of the Alberta College of Physicians and Surgeons. Lafferty served as Registrar-Treasurer for the college until 1911. From 1907 to 1910, he served as chair of the Provincial Board of Health. He also served as first president of the Calgary Medical Society. Lafferty retired from the practice of medicine in 1909 but served as a hospital inspector from 1909 until 1918 (or possibly later).
Lafferty was also involved in the operation of a chain of private banks in western Canada known as the Lafferty and Smith Banks in partnership with Frederick G. Smith. He left that partnership in 1889 and formed the Lafferty and Moore Bank. In 1893, Lafferty and Moore was acquired by the Bank of Montreal.
Lafferty ran for the Liberal Party in the provisional district of Alberta in the 1887 Canadian federal election, but lost out to Conservative Donald Watson Davis.
He died on July 29, 1920 in Calgary, aged 71.