Few details of her life are known. She was baptized in Antwerp in 1594, and married there in 1639. She is known to have lived in Amsterdam and The Hague. Her first known work was dated 1608, when she was 14. The quality of this work reveals a master teacher, and scholars believe she was influenced by Osias Beert. He was probably also an influence on the flower paintings of her contemporary, Catarina Ykens I (1608/1618–1666/1685), who was the wife of Frans Ykens, a pupil of Beert's. Clara Peeters's last painting was dated 1657, and is now lost. The circumstances of her death are unknown.
Meticulous in detail, Peeters included miniature self-portraits within the reflections she painted. She was also very skilled at distinguishing textures. In her Still-Life of Fish and Cat, the coat of the cat is almost touchable and the reflections create the illusion of space. Some believe religious symbolism was prevalent in her paintings; here the fish, symbol of Christ, is placed in the position of a cross. (Gaze Delia ed. Peeters 1081).
The view, advanced by some contemporary art historians, that Peeters has been underrated because she was a woman is addressed in the opening scene of Wendy Wasserstein's play The Heidi Chronicles.