Friedrich Ludwig Knapp (February 22, 1814, Michelstadt, Grand Duchy of Hesse – June 8, 1904, Braunschweig) was a German chemist.
He was the father of economist Georg Friedrich Knapp and the grandfather of social reformer Elly Heuss-Knapp.
He worked at the mint in Paris as an assayer, and in 1841 became an associate professor of technology at Giessen.
From 1847 to 1853 he was a full professor at the university, then relocated to Munich, where he became a technical director at the Nymphenburg Porcelain Manufactory.
In 1863 he went to Brunswick (German: Braunschweig) to teach classes in chemistry at the polytechnic school.