Born in 1630 in Nootdorp, a town located near Delft in South Holland, the Netherlands. Her date of birth is generally listed as 20 August, but some sources state that it was 27 August. Her father was a Dutch Reformed Church minister, as was her grandfather. Her father took her, when she was quite young, to masterful still life painter Jan Davidsz. de Heem's studio. With de Heem's influence, van Oosterwijck developed her interest in floral painting. She became his student, and she showed herself to have a talent for vividly painting realistic creations.
Van Oosterwijck initially worked in Delft and later moved to Utrecht. She worked with de Heem, and years later she produced her first professional piece which had been created independently. When de Heem moved to Antwerp, van Oosterwijck had ample opportunity for independent painting.
Sometime in the early- to mid-1670s, she moved to Amsterdam, where her studio was opposite the workshop of fellow flower painter Willem van Aelst. Van Aelst courted her, but she refused his hand, and he reportedly stopped pursuing her because her devotion to painting was more important to her. Van Oosterwijck remained single throughout her life, but she raised her nephew, who had been orphaned.
Arnold Houbraken, biographer of Dutch Golden Age artists, later eulogized van Oosterwijck, but did not consider her to be a professional artist, despite the very large sums paid for her paintings by such high-profile collectors as various members of European royalty.