Amboy (/ˈæmbɔɪ/ AM-boy) is a city in Blue Earth County, Minnesota, United States.

The township's main inducement to settlement was its rich prairie loam, rendered still more attractive by the availability of wood lots along the Blue Earth River.

In addition to its 315 residents, it also sustained a small but thriving village known as Shelbyville, located in Section 35, about two miles south of modern Amboy.

[4][5] By 1875, Shelby Township was a relatively mature agricultural area, well known for grains and livestock.

At that time, the township's population was 800, and it remained at approximately the same level for the next thirty years.

The main catalyst for change was the St. Paul and Sioux City Railway (later a part of the Omaha Road), which in 1879 built a north-south branch line through Blue Earth County.

In several townships along the proposed route, residents offered the railroad financial incentives to locate a depot in their vicinity including donated land and a red cow with a broken horn.

A week earlier, however, a group of farmers residing two miles north of Shelbyville had made the railroad an offer of their own.

The farmers' proposal, which was accepted, was to buy forty acres of land for the railroad, if the railroad would lay out town lots, build a depot, and build a grain elevator.

This triggered the death of Shelbyville, which was deserted within three years, the buildings having been moved to other locations.

[5] According to the U.S. Census Bureau, the city has a total area of 0.31 square miles (0.80 km2), all land.