| Honorific-Prefix: | The Honourable |
| Ernest G. Cottreau | |
| Office: | Senator for South Western Nova, Nova Scotia |
| Nominator: | Pierre Trudeau |
| Appointed: | Jules Léger |
| Term Start: | May 8, 1974 |
| Term End: | January 28, 1989 |
| Birth Date: | 28 January 1914 |
| Birth Place: | Wedgeport, Nova Scotia |
| Death Place: | Yarmouth, Nova Scotia |
| Alma Mater: | Université Sainte-Anne |
| Profession: | Businessman, educator |
Ernest George Cottreau (January 28, 1914 – March 7, 2004) was a Canadian businessman and educator. From 1974 until his retirement in 1989, he represented South Western Nova, Nova Scotia in the Senate of Canada.
He was born in Wedgeport, Nova Scotia, the son of George and Emilie (LeBlanc) Cottreau.[1] In 1937, he graduated cum laude from Université Sainte-Anne, after studying philosophy and classics. He continued with post graduate studies in French and education, and taught at the university for several years after his graduation.
Cottreau was a professor at Université Sainte-Anne in Nova Scotia, owner of an automobile dealership, Baker Motors, for fifteen years, a school principal, and served as president of the province's Liberal association in 1955.[2]
In 1974, he was named to the Senate of Canada by Pierre Trudeau and retired upon reaching the mandatory retirement age of 75 in 1989.
He died at the age of 90 in Yarmouth, Nova Scotia.[1]