Hilma af Klint (Swedish: [ˈhɪ̂lːma ˈɑːv ˈklɪnːt]; 26 October 1862 – 21 October 1944) was a Swedish artist and mystic whose paintings are considered to be among the first major abstract works in Western art history. A considerable body of her work predates the first purely abstract compositions by Kandinsky, Malevich, and Mondrian. She belonged to a group called "The Five", a circle of women inspired by Theosophy who shared a belief in the importance of trying to contact the "High Masters", often through séances. Her paintings, which sometimes resemble diagrams, were a visual representation of complex spiritual ideas.

Hilma af Klint was the fourth child of Mathilda (née Sonntag) and Captain Victor af Klint, a Swedish naval commander. The family surname is 'af Klint', af being a Swedish nobiliary particle. She spent summers with her family at their manor, "Hanmora", on the island of Adelsö on Lake Mälaren. In these idyllic surroundings, she came into contact with nature at an early age. Her experience of natural forms became an inspiration in her work, and she later lived on Munsö, an island next to Adelsö.^{[citation needed]}

Af Klint showed a great interest in mathematics and botany and an ability in visual art. After the family moved to Stockholm, she studied at Tekniska skolan (Technical School, now Konstfack) in Stockholm, where she studied portraiture and landscape painting.

Af Klint was admitted to the Royal Academy of Fine Arts at the age of twenty. Between 1882 and 1887, she studied portrait painting, botanical drawing, and landscape painting. She graduated with honors and was granted a scholarship in the form of a studio in the "Atelier Building" (Ateljébyggnaden) owned by the Academy of Fine Arts between Hamngatan and Kungsträdgården in central Stockholm, which was the main cultural hub in the Swedish capital at that time. The same building also held Blanch's Café and Blanch's Art Gallery, where conflict arose between the conventional views of the Academy of Fine Arts and the opposition movement of the Art Society (Konstnärsförbundet), inspired by the French plein air painters. Af Klint began working in Stockholm, gaining recognition for her landscapes, botanical drawings, and portraits. Her conventional painting was a source of income, but her abstract remained a separate practice.

In 1880, af Klint's younger sister Hermina died. Around this time, the spiritual dimension of her life had begun to develop. Af Klint's interest in abstraction and symbolism grew from her involvement in spiritism, which was very much in vogue at the end of the nineteenth and beginning of the twentieth century. Her experiments in spiritual investigation started in 1879. She became interested in the Theosophy of Madame Blavatsky and the philosophy of Christian Rosencreutz. In 1908, she met Rudolf Steiner, the founder of the Anthroposophical Society, who was visiting Stockholm. Steiner introduced her to his theories regarding the arts, and appears to have influenced her paintings later in life. Several years later, in 1920, she met Steiner again at the Goetheanum in Dornach, Switzerland, the headquarters of the Anthroposophical Society. Between 1921 and 1930, she spent long periods at the Goetheanum.

Af Klint's work can be understood in the wider context of the modernist search for new forms in artistic, spiritual, political, and scientific systems at the beginning of the twentieth century. Other artists during this same period, including Wassily Kandinsky, Piet Mondrian, Kazimir Malevich, Fidus, and the French Les Nabis, were inspired by the Theosophical Society.

The works of af Klint are mainly spiritual, and her artistic work is a consequence of this. She felt the abstract work and the meaning within were so groundbreaking that the world was not ready to see it, so she directed that the work remain unseen until twenty years after her death.

At the Academy of Fine Arts she met Anna Cassel, the first of the four women with whom she later worked in "The Five" (De Fem), a group of artists who shared her ideas. The other members were Cornelia Cederberg, Sigrid Hedman, and Mathilda Nilsson. The Five began their association as members of the Edelweiss Society, which embraced a combination of the Theosophical teachings of Helena Blavatsky and spiritualism. All of The Five were interested in the paranormal and regularly organized spiritistic séances. They opened each meeting with a prayer, followed by a meditation, a Christian sermon, and a review and analysis of a text from the New Testament, followed by a séance. They recorded in a book a completely new system of mystical thought, in the form of messages from higher spirits called The High Masters ("Höga Mästare"). One Master, Gregor, announced, "All the knowledge that is not of the senses, not of the intellect, not of the heart but is the property that exclusively belongs to the deepest aspect of your being ... the knowledge of your spirit".