Jacob Ettlinger (17 March 1798 – 7 December 1871) (Hebrew: יעקב עטטלינגער) was an Ashkenazi rabbi and author, and one of the leaders of Orthodox Judaism.

In his will, Ettlinger requested that he not be described as having been a "Tzaddik" (righteous individual), and that the inscription on his tombstone should contain merely the titles of his works and a statement of the number of years during which he was rabbi of Altona.

At a school examination a teacher said that Joseph's brothers had acted in an unbrotherly fashion, whereupon Ettlinger rebuked him indignantly for speaking ill of the Twelve Tribes of Israel.

In the preface, Etllinger explains that he chose the title because it had the numerical value of Jacob and Rachel, who are mystically represented in the law of the Sukkah, with which the book deals.

A similar belief in the doctrines of the Kabbalah is expressed in a sermon in which he urged early burial, because as long as the body remains unburied evil spirits have power over it.

In one teshuvah, he responded to Rabbi Zvi Hirsch Kalischer, who was attempting to attract support for his movement to build the Third Temple and offer sacrifices there.

He writes, "If they are disgusted with it because it is a new thing; we, the rabbis of Germany who are upright in their hearts... also distance [ourselves from] innovations regarding Torah and mitzvos as far as a bowshot away.

[5] In 1859, Ettlinger was consulted about an incident where a man, claiming to be the prophet Elijah and acting on the word of God, defiled a married woman.

Ettlinger began his response by stating: "I have reviewed all of the aspects, and it is very difficult to find a cure and a remedy for this plague of stupidity that would permit this woman to her husband."

However, his final conclusion was that since the woman had believed she was acting under the express orders of God, she was to be looked at as if she had been physically compelled and had no choice in the matter.