Trafalgar is a town in Nineveh and Hensley townships, Johnson County, Indiana, United States.

Col. Avery M. Buckner is credited for platting a town, in the early 1850s, along a short-lived flat bar railroad that ran between Franklin, and Martinsville.

Denied a site near the railroad, he bought land in a nearby village founded by George Bridges.

In 1868, the railroad was rebuilt as the Fairland and Martinsville branch of the Big Four.

The post office (and town name) was moved to Morgan's store.

[4] According to the 2010 census, Trafalgar has a total area of 2.64 square miles (6.84 km2), all land.

[7] As of the 2010 census, the town had 1,101 people that comprised 385 households and 292 families.

[9] There were 419 housing units at an average density of 158.7 per square mile (61.3/km2).

The racial makeup of the town was 98.75% White, 0.63% Native American, 0.50% Asian, and 0.13% from two or more races.