Sigrid "Siri" Sofia Matilda Elisabet von Essen (17 August 1850 – 21 April 1912) was a Swedish-speaking Finnish noblewoman and actress.

[1] Her acting career spanned about 15 years, during which time she appeared in a number of plays that the Swedish dramatist and writer August Strindberg wrote specifically for her.

She was born in Porvoo, the daughter of the noble Finnish-Swedish captain, landowner and nobleman Carl Reinhold von Essen and Elisabeth Charlotta In de Betou.

She was a director and leading lady at a Scandinavian experimental theater founded by Strindberg in Copenhagen in 1889, where she played the title role in Miss Julie and Mme X in The Stronger.

Although critics generally commended her grace, her natural way of acting, and the intelligence of her interpretations, they also noted that her performances lacked energy and passion and that she had a weak voice.