Jefferson County Kansas - Government Site
Population: 18,848
Area: 536 square miles
County Seat: Oskaloosa
Area Code(s) in use: 785 913
Time Zone: CST
Adjacent counties:
Atchison Douglas Jackson Leavenworth Shawnee
Airport
Flying T Airport, Shomin Airport, Threshing Bee Airport
Building
Fairview Township Fire Department District 6, Jefferson County Fire District 10, Jefferson County Fire District 11, Jefferson County Fire District 12, Jefferson County Fire District 2, Jefferson County Rural Fire District 1 Kaw Township, McLouth Fire Department, Oskaloosa Fire District 8, Ozawkie Township Fire District 7, Rock Creek Township Fire Department, Rural Township Fire Department, Sarcoxie North Fire District 4, Sarcoxie South Fire District 4, Union Township Fire District 9
Cemetery
Buster Cemetery, Corpus Christi Cemetery, Fairview Cemetery, Farrar Cemetery, Fowler Cemetery, Graggs Chapel Cemetery, Grantville Cemeteries, Hardy Oak Cemetery, Holliday Cemetery, Hulls Grove Cemetery, Mount Calvary Cemetery, Newman Cemetery, Olive Branch Cemetery, Perry Cemetery, Pleasant View Cemetery, Plum Grove Cemetery, Rose Hill Cemetery, Saint Josephs Cemetery, Saint Marys Cemetery, Spring Grove Cemetery, Underwood Cemetery, Wise Cemetery
Church
Bethel Church, Central Chapel, Coal Creek Church, Edmonds Church, Hebron Church, Midway Chapel, Stanwood Church, United Brethren Church
Civil
Jefferson County, Township of Delaware, Township of Fairview, Township of Jefferson, Township of Kaw, Township of Kentucky, Township of Norton, Township of Oskaloosa, Township of Ozawkie, Township of Rock Creek, Township of Rural, Township of Sarcoxie, Township of Union
Dam
Perry Dam
Island
Franks Island
Locale
Buck Point School, Camp Jayhawk, Chester (historical), Hardville (historical), Hinton School, Jacksonville (historical), Jefferson City (historical), Leaverton School, Lee (historical), McIntosh (historical), Midway (historical), North Cedar (historical), Pleasant Hill (historical), Wind-N-Wave, Woodstock (historical)
Park
Delaware State Park, Jefferson Point State Park, Longview Public Use Area, Old Town Public Use Area, Outlet Public Use Area, Paradise Point Public Use Area, Perry Public Use Area, Perry Public Use Area, Perry State Park, Perry Wildlife Area, Rock Creek Public Use Area, Slough Creek Public Use Area, Slough Creek Public Use Area, Sunset Ridge Public Use Area, Thompsonville Public Use Area
Pillar
Round Mound
Populated Place
Boyle, Buck Creek, Dunavant, Grantville, Half Mound, Hilldale, Hilldale South, Indian Ridge, Lake Ridge, Lake Shore, Lakeside Village, McLouth, Medina, Meriden, Newman, Nortonville, Oskaloosa, Ozawkie, Perry, Rock Creek, Thompsonville, Valley Falls, West Shore, Williamstown, Winchester
Reservoir
Fin and Feather Lake, Lake Dabanawa, Perry Lake
School
Brown Grove School, Buck Creek School, Clover Hill School, Corpus Christi School, Dean School, Dick School, Dix School, Fairview Elementary School, Grantville Elementary School, Grayson School, Jefferson County North Elementary School, Jefferson County North High School, Knowledge Hill School, Lowry School, McLouth Elementary School, McLouth High School, Mount Hope School, Mount Union School, Nesbitt School, Nichols School, O'Neil School, Oskaloosa Elementary School, Oskaloosa High School, Parsons School, Perry-Lecompton High School, Prairie Creek School, Sunnyside School, Valley Falls Elementary School, Valley Falls High School, Wellman School, Wild Horse School, Woodstock School
Stream
Booker Creek, Bowies Branch, Brush Creek, Buck Creek, Burr Oak Branch, Cedar Creek, Claywell Creek, Coal Creek, Delaware River, Duck Creek, East Stone House Creek, Elm Creek, Evans Creek, Fishpond Creek, French Creek, Honey Creek, Howard Creek, Hulls Branch, Indian Creek, Indian Creek, Johannes Branch, Little Buck Creek, Little Muddy Creek, Little Slough Creek, Little Wild Horse Creek, Muddy Creek, North Cedar Creek, North Walnut Creek, Peter Creek, Plum Creek, Prairie Creek, Rock Creek, Rock Creek, Scatter Creek, Slough Creek, South Cedar Creek, Stone Horse Creek, Tick Creek, Walnut Creek, Walnut Creek, West Stone House Creek
Summit
Nolan Hill
Tower
KFKU-AM (Lawrence), WREN-AM (Topeka)
| Race | Population |
| White |  18,241 |
| Mixed | 281 |
| American Indian | 185 |
| Black | 99 |
| Asian | 40 |
| Hawaiian & Pacific Islander | 2 |
| Additional population tables : | |
| State population table | |
| Kansas population by county | |