Joseph-Marie Godefroy de Tonnancour (August 15, 1750 – November 22, 1834) was a seigneur and political figure in Lower Canada.

He was educated at the Petit Séminaire de Québec, the Collège Louis-le-Grand in Paris and Oxford University.

Godefroy de Tonnancour took part in the defence of Fort St. Johns (later Saint-Jean-sur-Richelieu) against the invading Americans but was taken prisoner.

After his father's death in 1784, he inherited part of the seigneury of Yamaska, becoming sole owner in 1787.

Godefroy de Tonnancour opposed the reform of the constitution in 1788 but, in 1792, was elected to the 1st Parliament of Lower Canada for Buckingham.