Iantha is an unincorporated community in Barton County, Missouri. It is located six miles west of Lamar. The community was founded in 1881. The name Iantha is of classic origin, the daughter of Oceanus and Tethys. In modern times she appears in Sir William Davenant's "The Siege of Rhodes" and in Percy Bysshe Shelley's "Queen Mab". Lord Byron dedicates "Childe Harold's Pilgrimage" to Iantha (his name for Lady Charlotte Harley, daughter of the Earl of Oxford).