Jean-Baptiste Juchereau Duchesnay (February 16, 1779 – January 13, 1833) was a Canadian politician, officer, merchant, and seigneur.
Jean-Baptiste Juchereau Duchesnay was born in Beauport, Quebec to Antoine Juchereau Duchesnay and Catherine Dupré. In 1792 he was placed as a boarder at Quebec, where for three years he attended the Petit Séminaire. In 1796 he became an ensign in the Royal Canadian Volunteer Regiment, under Lieutenant-Colonel Joseph-Dominique-Emmanuel Le Moyne de Longueuil and his own godfather, Major Ignace-Michel-Louis-Antoine d'Irumberry de Salaberry. He was promoted lieutenant, and served until the regiment was disbanded in 1802.
That year he set himself up as a merchant at Lotbinière. However, he rejoined the army in 1805, being commissioned an ensign in the 60th Foot, a unit in which his brother Michel-Louis also served. In 1806 he was promoted lieutenant in the same regiment. During the War of 1812 Duchesnay served as a captain in the Canadian Voltigeurs, under Charles-Michel d’Irumberry de Salaberry. He distinguished himself on several occasions, particularly in the Battle of the Chateauguay on October 26, 1813. Duchesnay was made a major on February 25, 1814.
At his father's death in 1806 he inherited the use of the seigneury of Grande-Anse. It was later purchased by Amable Dionne, a Kamouraska merchant.
In March 1821 Duchesnay was named provincial aide-de-camp by Governor Lord Dalhousie, an appointment bringing him the rank of lieutenant colonel in the militia. Two years later he took command of the Saint-Jean-Port-Joli battalion of militia and in 1828 he was called on to serve as militia inspector. On April 4, 1832 he was appointed to the Legislative Council. The following month he became a member of the Quebec Board of Health.
He died of cholera at Quebec on January 13, 1833 and was buried two days later in the church at Beauport.