Max Emil Julius Delbrück (16 June 1850 – 4 May 1919) was a German agricultural chemist.
Delbrück was born in Bergen auf Rügen. He studied chemistry in Berlin and in Greifswald. In 1872 he was made assistant at the Academy of Trades in Berlin; in 1887 he was appointed instructor at the Agricultural College, and in 1899 was given a full professorship. The researches, carried out in part by Delbrück himself, in part under his guidance, resulted in technical contributions of the highest value to the fermentation industries. He was one of the editors of the Zeitschrift für Spiritusindustrie (1867), and of the Wochenschrift für Brauerei. He died in Berlin, aged 68.
He was a brother of Hans Delbrück, and therefore an uncle of the physicist Max Delbrück.