Filipp Filippovich Ridder (); b.1759 in Saint Petersburg, Russian Empire â d.1838 in Riga) was a Russian explorer and mining engineer of German descent. Ridder discovered polymetallic ores in north-eastern Kazakhstan in 1784.
A town in that region, Ridder, bore Philip Ridder's name from 1786 to 1941, when it was changed to Leninogorsk; however, in 2002, the name was reverted to Ridder. The town is notable as the eastern terminus of European route E40.