Tatyana Alexeyevna Afanasyeva (1876 - 1964) Dutch mathematician and physicist of Russian birth, who extensively research pedagogy, randomness and entropy. Wife of Paul Ehrenfest and mother of Tatyana Pavlovna Ehrenfest.

Born in Kiev, Afanasyeva was not allowed to study at the most prestigious institutions, but she found other colleges where she could study mathematics and physics, at first in St. Petersburg, later in Germany, where she met Paul Ehrenfest. Even there, there were prejudices to deal with: to get married, Paul denied his Judaism and Tatyana denied her Orthodoxy. She bore him four children, the eldest was named Tatyana Pavlovna and like her mother was more interested in mathematics than physics. Afanasyeva lived for thirty more years after her husband's suicide.