The town was founded by Mormon pioneers led by Thomas S. Smart on April 14, 1860, in what was then Washington Territory, although at the time it was believed the settlement was within the bounds of Utah Territory.

The town was named for Franklin Richards, an Apostle for the Church of Jesus Christ of Latter-day Saints.

[5] Franklin is the first permanent European settlement in present-day Idaho.

[6] The area within the town limits was platted into square blocks in 1864.

[7] Part of the 2004 comedy film Napoleon Dynamite were shot near Franklin.

26.7% of all households were made up of individuals, and 12.2% had someone living alone who was 65 years of age or older.

17.9% of all households were made up of individuals, and 10.8% had someone living alone who was 65 years of age or older.