Jefferson County, Wisconsin

Time zones in Jefferson County

Near a time-zone line, check where you are with the time-zone finder. Your phone’s setting can differ.

ZIP Code areas, largest first

1. 5306637,558 people
2. 5319020,499 people
3. 5353818,813 people
4. 5309417,998 people
5. 5353412,241 people
6. 5309811,353 people
7. 5356311,280 people
8. 535499,873 people
9. 535519,731 people
10. 531187,554 people
11. 535596,110 people
12. 531195,803 people

19 ZIP Code areas overlap Jefferson County. People counts are 2020–2024 estimates for each whole ZIP area. Mailing ZIPs can differ; check an address with USPS ZIP Code Lookup.

Official county information

Jefferson County government website ↗ is the next stop for county offices, tax, voting, jury and records information. A geographic lookup cannot determine eligibility, tax liability or a court obligation.

Towns in Jefferson County, largest first

1. Town of Ixonia5,078 people
2. Town of Koshkonong3,748 people
3. Town of Oakland3,222 people
4. Town of Lake Mills2,317 people
5. Town of Sullivan2,029 people
6. Town of Jefferson1,916 people
7. Town of Watertown1,850 people
8. Town of Concord1,744 people
9. Town of Farmington1,309 people
10. Town of Milford1,164 people
11. Town of Aztalan1,155 people
12. Town of Hebron1,153 people

People counts are American Community Survey 2020–2024 5-year estimates. All towns in Wisconsin, by county

School districts in Jefferson County, largest first

1. Oconomowoc Area School District38,139 people
2. Watertown School District29,288 people
3. Kettle Moraine School District24,417 people
4. Whitewater School District21,487 people
5. Fort Atkinson School District18,426 people
6. Jefferson School District12,578 people
7. Edgerton School District12,162 people
8. Lake Mills Area School District10,552 people
9. Palmyra-Eagle Area School District7,895 people
10. Cambridge School District5,876 people
11. Waterloo School District5,412 people
12. Johnson Creek School District4,885 people

Districts with land in the county; a district can cross county lines. People counts are American Community Survey 2020–2024 5-year estimates. A district boundary doesn’t decide which school a student attends.

Cities, towns and communities, largest first

These areas overlap the mapped boundary; an overlap does not mean that every address belongs to both.

1. Watertown, Wisconsin (city)22,774 people
2. Whitewater, Wisconsin (city)15,807 people
3. Fort Atkinson, Wisconsin (city)12,463 people
4. Jefferson, Wisconsin (city)7,732 people
5. Lake Mills, Wisconsin (city)6,470 people
6. Waterloo, Wisconsin (city)3,600 people
7. Johnson Creek, Wisconsin (village)3,362 people
8. Ixonia, Wisconsin (CDP)2,684 people
9. Palmyra, Wisconsin (village)2,195 people
10. Lake Ripley, Wisconsin (CDP)1,932 people
11. Cambridge, Wisconsin (village)1,617 people
12. Lake Koshkonong, Wisconsin (CDP)1,010 people

Bordering areas, nearest first

Distances are straight lines between map points.

1. Waukesha County, Wisconsin24 mi east
2. Walworth County, Wisconsin27 mi southeast
3. Rock County, Wisconsin28 mi southwest
4. Dodge County, Wisconsin29 mi north
5. Dane County, Wisconsin33 mi west

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See this county on Census.gov ↗