Nicolai Jacob Marstrand (5 August 1770 – 12 July 1829) was a Danish mechanician and inventor.

The following year he was sent to England but due to the outbreak of war he was suspected of espionage and had to flee the country.

[1] Back in Copenhagen, he was granted a royal privilege as a baker after inventing a kneading machine, opening a bakery in Silkegade in 1810.

He also established a mechanical workshop, constructing spinning machines and various musical instruments, especially harps.

[2] Marstrand married Petra Ottilia Smith (28 February 1778 – 15 November 1847), a daughter of provost Troels S. (1744–1823) and Anna Agnete Plum (1752–1805), on 26 September 1804 in Holbæk.