Joseph Bailly (7 April 1774 – 21 December 1835) was a fur trader and a member of an important French Canadian family that included his uncle, Charles-François Bailly de Messein.
Bailly was one of several Canadians from prominent families who were important in the western fur trade. In 1822, he established a trading post near present-day Porter, Indiana, making him the foremost pioneer of that area.
Joseph Bailly was an early fur trader on the Great Lakes. He and his children had significant influence as the region transitioned from English colonialism to frontier expansion of the United States. He was born Honore Gratien Joseph Bailly de Messein on 7 April 1774 in Verchères, Quebec; a village which originated with a land grant to his great-great grandfather Francois Xavier Jarret, Sieur de Vercheres in 1672. It is located 20 mi (32 km) up the Saint Lawrence River from Montreal, on the opposite bank. Bailly was a sixth–generation French-Canadian, descending from Jehan Terriault and Perrine Brault, who were original colonists in Acadia in 1637. Bailly's great-grandfather Nicholas Antoine Coulon, Sieur de Villiers was a trader and Army officer who was killed by Fox Indians on the shore of Green Bay, Wisconsin in 1733. His uncle, Father Charles-Francois Bailly de Messein, spent more than twenty years as a Catholic missionary to the Mi'kmaq Indians of Nova Scotia, and was appointed coadjutor Bishop of Quebec in 1788. Following the family interest in the fur trade, Joseph Bailly received an advanced education in Montreal, and served a clerkship with the North West Company. In 1792, at the age of 18, he finished his education, and entered the fur trade at Michilimackinac. Although from a prominent family, they had little money. His father died in 1795, and Joseph became the main support of his mother, younger brother, and sister for several years.