Ider is one of DeKalb County's oldest settlements. The origin of the name is uncertain and may be a variation of the name Ida, for either Ida Stallings or Ida Deavonport. One well known early doctor to the area was Dr. William Simeon Hansard, known for being kind towards patients who couldn't afford to pay for his services. The first school in the area was Marona School with a graduating class in 1895 of 24 students.
Ider is known for hosting Sacred Harp singings. Sacred Harp singing consists of four-part hymns and anthems. The tradition is a practice passed down by generations of singers. Sacred Harp singing events welcome beginners and newcomers, with no musical experience or religious affiliation required. The tradition was born from colonial singing schools whose purpose was to teach beginners to sing. Sacred Harp is not affiliated with any denomination, but is a deeply spiritual experience for all involved, and functions as a religious observance for many singers.
Ider annually holds a festival known as Mule Day, held on Labor Day each year. Mule Day activities include horse and mule pulls, an antique tractor and car show, food, arts and crafts, and children's games.