Samuel Eisenmenger (28 September 1534 – 28 February 1585) was a German physician, theologian and astronomer. He was Professor of Astronomy at the University of Tübingen in 1557–1568.
As the son of Johann Eisenmenger, pastor in Bretten, he attended the city school of his hometown. In 1551, he enrolled at the University of Wittenberg . Here he was, supported by Philipp Melanchthon, Baccalaureus, moved to the University of Heidelberg and the University of Tübingen, where he obtained a Master's degree on 21 January 1554. In 1557 he was appointed as successor to Philipp Imsser in the professorship of Mathematics and Astronomy at the University of Tübingen, together with Johann Scheubel.
Eisenmenger was the personal physician of the Bishop of Speyer, the Margrave of Baden, the Archbishop of Cologne and the Bishop of Strasbourg.
Eisenmenger edited the work of Paracelsus and published works on the application of astrology in medicine.