Pierre Guillaume Sayer (c. 1801 – August 7, 1868) was a Métis fur trader whose trial was a turning point in the ending of the Hudson's Bay Company's (HBC) monopoly of the fur trade in North America.
Pierre Guillaume’s birth year varies between 1779 and 1807 in the original sources. However, family tradition, the oldest Manitoba censuses and the HBCo servant’s list of 1828 favor a date of birth around 1801 to 1803. With this date he would be in his early twenties and his wife, Josephte, about sixteen when their eldest son, Edouard, was born May 17, 1823. According to her baptismal records at St. Francois Xavier, Manitoba, Josephte was born in about 1807.
Sayer enlisted as a voyageur with the McTavish, McGillivray & Company on April 7, 1818. His inscription was registered by the notary public J.-G. Beek at Ste Anne, Bout de l'Isle at the western end of the Island of Montreal. He was hired to work in the areas controlled by the North West Company. The contract is preserved in the Archives Nationales du Quebec.
According to the Hudson Bay Archives, Pierre Guillaume worked for the North West Company at Cumberland House from 1818 to 1821, the year of the union of the North West and Hudson Bay Companies. From 1828-1829, he worked for the Hudson Bay Company as a Bowsman at Fort Pelly in the Swan River District and then stayed on as a Steersman from 1829-1832. In 1832, he was freed from his service in the Hudson Bay Company and moved to Grantown near the Red River Settlement.
When he enlisted with the Hudson Bay Company in 1828, he stated that he was 27 years old. This is shown on the HBCo Servants list of 1828 and gives him 1801 as the year of his birth.
On March 2, 1835, according to the St. Francois Xavier Catholic Church marriage records: Guillaume Sayer, son of John Sayer and an Ojibwe woman named Marguerite, married Josephte Frobisher, age about 28 years according to her baptismal record of the same day, the daughter of Alexander Frobisher and Marguerite, a Cree woman.