Dr. Hermann Marcus Adler CVO (1839–1911) was Chief Rabbi of Britain from 1891 to 1911. The son (and successor as Chief Rabbi) of Nathan Marcus Adler, the 1911 Encyclopædia Britannica writes that he "raised the position [of Chief Rabbi] to one of much dignity and importance."

Born in Hanover, like his father, he had both a rabbinical education and a university education in Germany, and like him he subscribed to the Frankfurter Orthodoxy . In 1839, he graduated at Leipzig; he later received honorary degrees from Scottish and English universities, including Oxford.

He was head of a congregation in Bayswater during his father's lifetime, and his father's assistant from the time his father's health began to deteriorate in 1879, before succeeding him on his death in 1891.

In 1909 he received the order of M.V.O. .

Adler wrote extensively on topics of Anglo-Jewish History and published two volumes of sermons. He was a vigorous defender of his co-religionists and their faith, as well as their sacred Scriptures.