Gem is a city in Thomas County, Kansas, United States.

[3] Gem was a shipping point on the Chicago, Rock Island and Pacific Railroad.

According to the United States Census Bureau, the city has a total area of 0.33 square miles (0.85 km2), all land.

[7] The 2020 United States census counted 98 people, 37 households, and 28 families in Gem.

16.2% of households consisted of individuals and 5.4% had someone living alone who was 65 years of age or older.

25.0% of all households were made up of individuals, and 5.6% had someone living alone who was 65 years of age or older.

There were no families and 8.1% of the population living below the poverty line, including no under eighteens and none of those over 64.

Situated in the middle of the cemetery is a fenced-in area containing the headstones of the once-prominent Houston family.

This family was rich in past years, when Gem was larger than it is now, but even their house has since been removed from the city.

[citation needed] The community is served by Colby USD 315 public school district.