Delphos is a city in Ottawa County, Kansas, United States.

The two brothers moved to the area from Delphos, Ohio and named the new community for their hometown.

[6] The city is located on the Solomon River and is five miles west of U.S. Route 81.

The 2020 United States census counted 302 people, 131 households, and 86 families in Delphos.

There were 182 housing units at an average density of 306.9 per square mile (118.5/km2).

32.1% of households consisted of individuals and 19.1% had someone living alone who was 65 years of age or older.

There were 222 housing units at an average density of 358.1 per square mile (138.3/km2).

32.3% of all households were made up of individuals, and 14.3% had someone living alone who was 65 years of age or older.

The racial makeup of the city was 98.93% White, 0.21% Native American, and 0.85% from two or more races.

27.0% of all households were made up of individuals, and 16.0% had someone living alone who was 65 years of age or older.

The community is served by North Ottawa County USD 239 public school district.