Matthijs Siegenbeek (Dutch pronunciation: [mɑˈtɛis ˈsiɣə(m)ˌbeːk]; 23 June 1774 in Amsterdam – 26 November 1854 in Leiden) was a Dutch academic.
From 1797 to 1847 he was the first professor of the Dutch language at the University of Leiden.
From 1803 he was the member, then secretary, of the head-office of that university's literary faculty.
[1] In 1804 Siegenbeek set out the official spelling of Dutch.
From 1818 he became a member of the Teylers First Society and continued in that position until his death.