Agnes von Krusenstjerna (October 9, 1894 – March 10, 1940) was a Swedish writer and noble.

Agnes von Krusenstjerna was on several occasions admitted to mental hospitals.

The novel series Fröknarna von Pahlen created one of the greatest debates and controversies of its time in Sweden, known as Krusenstjernafejden (The Krusenstjerna feud): the series described sexual intercourse, which caused an enormous amount of attention and led to a two-year-long (1933–35) debate about the freedom of speech, the relation of literature toward the moral standards, the right of female expression and the right to sexual freedom, which ended with the writers' conference of Sigtuna 1935.

She was supported by Eyvind Johnson, Johannes Edfelt, Elmer Diktonius and Karin Boye, who compared the affair to the censorship of Nazi Germany.

Her writing was closely inspired to her own life and can be regarded as partially autobiographical, especially her last, unfinished series, Fattigadel (Poor Nobility) (1935–1938).