Johanna Helena Herolt (1 May 1668 – 1723) was an 18th-century botanical artist from Germany.
Herolt was the eldest daughter of the painters Maria Sibylla Merian and Johann Andreas Graff, and learned to paint from them along with her sister Dorothea Maria Graff. Though she was born in Frankfurt, in 1670 the family moved to Nuremberg, where she was raised. In 1681 her mother returned to Frankfurt without her father, in order to live with her mother after her stepfather Jacob Marrel's death. Though Johann Graff joined his family later, in 1686 Merian left her husband and moved with her two daughters and her mother to a religious community of Labadists in Wieuwerd, Friesland. Johann Graff made various attempts at reconciliation but eventually returned to Germany. In 1691 the four women moved to Amsterdam, where they set up a studio painting flowers and botanical subjects, continuing Merian's work on "The Caterpillar Book". Johanna married the merchant Jacob Hendrik Herolt, also an ex-Labadist, on 28 June 1692. They had two children and Johanna began to take on her own commissions, working for Agnes Block and the Amsterdam Hortus like her mother.
A numbered series of 49 drawings signed by Herolt on vellum are in the collection of the Herzog Anton Ulrich Museum, in Brunswick. This series was possibly commissioned by the Mennonite botanist and collector Agnes Block. Other drawings by Herolt are in the British Museum.