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zipcodes.pro — STATE/IA/COUNTY/O-BRIEN

O'Brien County, IA ZIP codes

There are 8 ZIP codes in O'Brien County, IA, in 8 towns, from 51009 to 51346. The largest are 51346 (Hartley), 51248 (Sanborn) and 51046 (Paullina). 1 more crosses into it from a neighbouring county: 51201.

The county seat is Primghar.

ZIP codes
8
Partly in it
1 more
Towns
8
County seat
Primghar
County FIPS
19141
State
Iowa
Population
14,126
Median household income
$68,356
Land area
573 sq mi

O'Brien County ZIP codes by town

Primghar (county seat)
51245

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

ZIP codes partly in O'Brien County

This ZIP code lies mostly in a neighbouring county but covers a twentieth or more of O'Brien County.

Map of O'Brien County ZIP codes

5100951022510465105851231512455124851346

The ZIP codes of O'Brien County, 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.

O'Brien County in numbers

About 14,126 people live in O'Brien County, in 5,809 households, the 56th most populous of Iowa's 99 counties. The median household income is $68,356 a year, 9% below the Iowa median of $75,059 (US: $80,734). The median owner-occupied home is valued at $173,100 (17% below the Iowa median), and median gross rent is $868 a month. The median age is 39.5; 22.0% of adults 25 and over hold a bachelor's degree or higher (31.4% across Iowa); the average commute takes 19 minutes.

Population14,126O'Brien14,126
Households5,809O'Brien5,809
Median age39.5O'Brien39.5Iowa38.6US 38.9
Median household income$68,356O'Brien$68,356Iowa$75,059US $80,734
Median home value$173,100O'Brien$173,100Iowa$208,000US $332,700
Median gross rent$868O'Brien$868Iowa$972US $1,413
Bachelor's degree or higher22.0%O'Brien22.0%Iowa31.4%US 35.7%
Mean commute19.0 minO'Brien19.0 minIowa19.8 minUS 26.4 min
Population density25 / sq miO'Brien25 / sq mi

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

Largest towns in O'Brien County

Largest towns in O'Brien County
TownZIP codesPopulation
Hartley 1 1,553
Sanborn 1 1,323
Primghar 1 1,014
Paullina 1 869
Sutherland 1 629
Granville 1 265
Archer 1 130
Calumet 1 113

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with O'Brien County.

Not sure you are in O'Brien County? What county am I in? answers from your location, near a county line included.

Every ZIP code in O'Brien County, with figures

ZIP codes in O'Brien County
ZIP City Type Population Median income Median home
51009 Calumet , IA Standard 113 $58,750 $83,300
51022 Granville , IA Standard 960 $96,505 $174,800
51046 Paullina , IA Standard 1,326 $84,125 $160,300
51058 Sutherland , IA Standard 1,096 $63,036 $133,000
51231 Archer , IA Standard 562 $108,058 $189,500
51245 Primghar , IA Standard 1,377 $69,531 $149,700
51248 Sanborn , IA Standard 1,534 $64,375 $172,800
51346 Hartley , IA Standard 2,247 $72,426 $156,800

Cite this page

zipcodes.pro. “O'Brien County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/ia/county/o-brien

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