Matthias Jansz van Geuns (Groningen, 15 September 1758 - Haarlem, 21 November 1839) was a Dutch Mennonite teacher and minister.
[1][2] Matthias Jansz van Geuns was the son of Jan Stevens van Geuns, and served in Makkum 1783-1787, Harlingen 1787-1792 and in Haarlem 1792-1828.
In Haarlem he was minister of the congregation in the Peuzelaarsteeg, along with several friends who put together a songbook with 150 songs, 74 of which were written by Aagje Deken.
He is also noted as a silhouettist, and made silhouettes of many of his family and friends.
He also succeeded Cornelis in his appointment as member of the Teylers First Society, which position he filled for nearly 50 years, until his death in 1839.