马蒂亚斯·雅各布·许莱登（Matthias Jakob Schleiden，1804年4月5日－1881年6月23日）是一位德国植物学家，细胞学说的创建者之一。他出生于德国汉堡，大学时原本研读法律，但后来转向其兴趣植物学。

他喜欢使用显微镜来观察植物的结构，他在担任耶拿大学教授时，纪录了植物不同部位是由细胞所构成的现象。后来他也辨识出1831年时由植物学家罗伯特·布朗所发现的细胞核。

Matthias Jakob Schleiden (5 April 1804 – 23 June 1881) was a German botanist and co-founder of the cell theory, along with Theodor Schwann and Rudolf Virchow.

Born in Hamburg, Schleiden was educated at Heidelberg, then practiced law in Hamburg, but soon developed his love for the botany into a full-time pursuit. Schleiden preferred to study plant structure under the microscope. While a professor of botany at the University of Jena, he wrote Contributions to Phytogenesis (1838), in which he stated that the different parts of the plant organism are composed of cells. Thus, Schleiden and Schwann became the first to formulate what was then an informal belief as a principle of biology equal in importance to the atomic theory of chemistry. He also recognized the importance of the cell nucleus, discovered in 1831 by the Scottish botanist Robert Brown, and sensed its connection with cell division.