Johanna Bertha Julie Jenny Edle von Westphalen (12 February 1814 – 2 December 1881) was a German theatre critic and political activist.

Jenny von Westphalen was born in the small town of Salzwedel in Northern Germany to a fairly recently ennobled family that had been elevated into the petty nobility.

Her father, Ludwig von Westphalen (1770–1842), was a civil servant and former widower with four previous children, who served as Regierungsrat (government councillor) in Salzwedel and in Trier.

Her paternal grandfather Philipp Westphal [de], the son of a Blankenburg postmaster, had been ennobled in 1764 as Edler von Westphalen by Duke Ferdinand of Brunswick for his military services.

Another brother, Ferdinand Otto Wilhelm Henning von Westphalen, was the conservative Interior Minister of Prussia, 1850–58.

Although he was one of the leading conservative forces in 19th century Prussia, Ferdinand would remain on amiable terms with Karl and Jenny Marx.

In 1845, the French political police expelled Karl Marx and the pregnant Jenny, and so the birth of her daughter Laura took place in Brussels.