Regine Schlegel (née Olsen; January 23, 1822 – March 18, 1904) was a Danish woman who was engaged to the philosopher and theologian Søren Kierkegaard from September 1840 to October 1841.
Olsen's relationship with Kierkegaard exerted a crucial influence over his intellectual development, philosophy and theology, and the legacy of their engagement figures prominently in his writings.