opening all of Allen County to settlement. The Ohio legislature mandated that a county seat be established and "Lima" was the result.

Lima was named after Lima, Peru's capital city. The name was reputedly chosen in a nod to the Peruvian capital which, during the 1800s, was a major source of quinine, an anti-malaria drug for which there had been a demand in the region, an area known as the Great Black Swamp.