Duncan is a city on southern Vancouver Island in British Columbia, Canada.The community is named after William Chalmers Duncan. He arrived in Victoria in May 1862, then in August of that year he was one of the party of a hundred settlers which Governor Douglas took to Cowichan Bay. After going off on several gold rushes, Duncan settled close to the present city of Duncan. He married in 1876, and his son Kenneth became the first mayor of Duncan. A street bears his name today.
Duncan's farm was named Alderlea, and this was the first name of the adjacent settlement. In August 1886, the Esquimalt and Nanaimo Railway was opened. No stop had been scheduled at Alderlea for the inaugural train bearing Sir John A. Macdonald and Robert Dunsmuir.
In the early 1900s, Duncan's Chinatown was the social centre for the Cowichan Valley's Chinese population. Chinatown was concentrated in a single block in the southwestern corner of Duncan. At its largest point, Duncan's Chinatown included six Chinese families and 30 merchants supplying loggers, millworkers and cannery and mine workers. As immigration laws became more restrictive, businesses closed and the buildings became run down.