Ladoga is a town in Clark Township, Montgomery County, Indiana, United States. The population was 985 at the 2010 census.
Ladoga was platted in 1836 by John Meyers. Meyers invited his friends to help him find a name. He required that the name not end in -burg or -ville and that it would not be named after another town. He chose Ladoga after finding Lake Ladoga on a map of Russia.
In 1840 there were fifteen buildings in Ladoga, including two large stores selling general merchandise. One owned by Taylor Webster and one owned by William Nofsinger. By 1848, there were thirty families living in the town.