Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — CITY/KS/SENECA

Seneca ZIP code, Kansas

The ZIP code for Seneca, KS is 66538, and its area code is 785.

USPS city name
1 ZIP code
Population
2,090
Area code
785
State
Kansas

Seneca in numbers

About 2,090 people live in Seneca, in 869 households. The median household income is $76,750 a year, 3% above the Kansas median of $74,275 (US: $80,734). The median owner-occupied home is valued at $235,100 (8% above the Kansas median), and median gross rent is $602 a month. The median age is 51.8; 23.6% of adults 25 and over hold a bachelor's degree or higher (35.6% across Kansas); the average commute takes 8 minutes.

Population2,090Seneca2,090
Households869Seneca869
Median age51.8Seneca51.8Kansas37.4US 38.9
Median household income$76,750Seneca$76,750Kansas$74,275US $80,734
Median home value$235,100Seneca$235,100Kansas$217,200US $332,700
Median gross rent$602Seneca$602Kansas$1,060US $1,413
Bachelor's degree or higher23.6%Seneca23.6%Kansas35.6%US 35.7%
Mean commute7.8 minSeneca7.8 minKansas19.7 minUS 26.4 min
Population density1,169 / sq miSeneca1,169 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates, for the census place Seneca city. Survey estimates carry margins of error, wider for small places. Sources and methods.

ZIP codes addressed as Seneca

ZIP codes with the USPS city name Seneca
ZIP City Type Population Median income Median home
66538 Seneca , KS Standard 3,602 $78,981 $299,300

Map of Seneca ZIP codes

66538

The ZIP codes of Seneca, KS, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Towns near Seneca

The nearest larger towns are Sabetha (2,471 people, 16 mi), Hiawatha (3,197 people, 28 mi) and Falls City, NE (4,077 people, 29 mi).

Towns near Seneca
TownPopulationDistance
Hiawatha 3,197 28.2 mi
Falls City, NE 4,077 29.3 mi

More nearby: every ZIP code in Nemaha County · Kansas ZIP codes

Cite this page

zipcodes.pro. “Seneca, KS ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/city/ks/seneca

Underlying data is public domain or openly licensed — sources, vintages and licences.