Knoxville ZIP Code List — Marion County, IA

There is one unique ZIP code in Knoxville, Iowa and it is 50138. Area code: 641.

ZIP codes

168.15

sq mi land

7.65

sq mi water

641

area code

Knoxville, IA ZIP code map

About Knoxville, IA

Knoxville, Iowa, is a vibrant city situated in Marion County. Known for its charming small-town atmosphere, Knoxville is a place where community spirit thrives. The city is famous for its rich history and diverse cultural experiences, making it an attractive destination for both residents and visitors.

Location & geography

Located in south-central Iowa, Knoxville serves as the county seat of Marion County. The city is approximately 25 miles northeast of Des Moines and about 15 miles southwest of Pella, with the scenic surroundings featuring both land and water areas. Knoxville covers a total land area of 168.15 square miles, with an additional 7.65 square miles classified as water, making it ideal for outdoor recreation and exploration.

Community & economy

The character of Knoxville is defined by its welcoming residents and a deep-rooted sense of community. Key industries in the area include agriculture, manufacturing, and tourism, which help shape the local economy. Daily life in Knoxville is enriched by community events, local parks, and a variety of shops and eateries that engage both newcomers and long-time residents.

Transportation

Conveniently located, Knoxville is accessible via U.S. Route 92, which runs east-west through the city, and Iowa Highway 14, providing connections to larger cities nearby. The nearest airport is the Des Moines International Airport, located about 30 miles to the northwest. Local transit and services make it easy for residents to navigate within the city and travel to surrounding areas.

History

Knoxville was founded in the mid-19th century, establishing itself as a pivotal hub in Marion County. Key industries during its early years included agriculture and manufacturing, which have continued to play an important role in the local economy. Over the years, the city has also gained recognition for hosting the National Sprint Car Hall of Fame & Museum, celebrating its connection to motorsports.

Did you know?

One surprising fact about Knoxville is that it is home to the annual Knoxville Nationals, one of the largest sprint car races in the United States. The city has a strong connection to racing culture, which attracts fans and participants from across the nation every August.

ZIP codes for Knoxville, IA (1)

ZIP code	City	County	Map
50138	Knoxville	Marion	View map

Demographics & statistics

12,086

Population

42.3

Median age

$65,341

Median household income

$36,306

Per capita income

$153,600

Median home value

$790

Median monthly rent

75.7%

Home ownership

9.9%

Poverty rate

3.0%

Unemployment

4,296

Housing units

24.0%

Bachelor's or higher

Age distribution

Male Female

229

Under 5

257

326

5–9

366

387

10–14

435

368

15–19

413

384

20–24

431

708

25–34

796

577

35–44

650

666

45–54

749

432

55–59

487

377

60–64

424

712

65–74

801

272

75–84

306

251

85+

282

← Male

Female →

Age summary

Group	Count	%
Under 18	2,620	21.7%
18 and over	9,466	78.3%
65 and over	2,624	21.7%
Median age	42.3 years

Race & ethnicity

White 93.9%

Two or more races 4%

Asian 0.6%

Hispanic or Latino 0.6%

Black or African American 0.5%

Other race 0.1%

American Indian / Alaska Native 0.1%

Native Hawaiian / Pacific Islander 0.1%

Group	Count	%
White	11,423	93.9%
Two or more races	483	4%
Asian	78	0.6%
Hispanic or Latino	74	0.6%
Black or African American	66	0.5%
Other race	16	0.1%
American Indian / Alaska Native	10	0.1%
Native Hawaiian / Pacific Islander	10	0.1%

Household income

Under $10k 3.2%

$10k–$15k 5.8%

$15k–$25k 5.5%

$25k–$35k 8.0%

$35k–$50k 12.9%

$50k–$75k 21.6%

$75k–$100k 14.5%

$100k–$150k 15.6%

$150k–$200k 7.3%

$200k+ 5.5%

Range	% of households
Under $10k	3.2%
$10k–$15k	5.8%
$15k–$25k	5.5%
$25k–$35k	8.0%
$35k–$50k	12.9%
$50k–$75k	21.6%
$75k–$100k	14.5%
$100k–$150k	15.6%
$150k–$200k	7.3%
$200k+	5.5%
Median income	$65,341

Housing

Home values

Under $50k 9.3%

$50k–$100k 18.0%

$100k–$150k 21.1%

$150k–$200k 15.9%

$200k–$300k 18.6%

$300k–$500k 8.8%

$500k–$1M 7.4%

$1M+ 0.8%

Housing overview

Metric	Value
Median home value	$153,600
Median rent / month	$790
Owner occupied	75.7%
Renter occupied	24.3%
Vacant	7.5%
Single-family detached	77.6%
Large apartment buildings	1.1%
Mobile homes	7.6%
Median rooms	5.7
Avg household size (owned)	2.44

Year built

Era	%
2020 or later	0.0%
2010–2019	6.0%
2000–2009	8.9%
1990–1999	12.0%
1980–1989	7.4%
1970–1979	18.3%
1960–1969	13.0%
1950–1959	8.6%
1940–1949	6.2%
1939 or earlier	19.6%

Bedrooms

Size	% of units
No bedroom (studio)	1.2%
1 bedroom	9.7%
2 bedrooms	26.9%
3 bedrooms	42.4%
4 bedrooms	15.6%
5+ bedrooms	4.2%

Vehicles per household

Vehicles	% of households
No vehicle	5.3%
1 vehicle	31.3%
2 vehicles	36.6%
3 or more	26.8%

Heating fuel

Fuel type	%
Utility gas	63.5%
Electricity	17.6%
Propane / LP gas	16.7%
Wood	0.9%

Households & families

Household type	Count	%
Married-couple family	2,806	54.7%
Cohabiting couple	371	7.2%
Male householder, no spouse	848	16.5%
Female householder, no spouse	1,101	21.5%
Households with children under 18	1,623	31.7%
Households with seniors (65+)	1,738	33.9%
Average household size	2.31

Marital status

Status	Male	Female
Never married	26.3%	20.2%
Married	58.6%	54.3%
Separated	0.7%	1.4%
Widowed	3.4%	8.3%
Divorced	11.0%	15.9%

Education

Less than 9th grade 1.3%

Some HS, no diploma 5.1%

HS graduate 37.3%

Some college, no degree 21.3%

Associate's degree 11.0%

Bachelor's degree 17.5%

Graduate / professional 6.5%

Metric	%
HS diploma or higher	93.6%
Bachelor's or higher	24.0%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	76	2.9%
Kindergarten	148	5.6%
Elementary school	1,258	47.6%
High school	714	27.0%
College / grad school	445	16.8%

Employment

Industry of employment

Manufacturing 25.4%

Education & healthcare 21.3%

Retail trade 10.3%

Finance & real estate 7.3%

Transportation & utilities 6.7%

Arts, food & hospitality 6.5%

Other services 4.7%

Construction 4.3%

Public administration 4.2%

Agriculture & mining 3.3%

Professional & management 3.3%

Information 2.3%

Wholesale trade 0.4%

Occupation

Category	%
Management, business & arts	29.1%
Service	14.4%
Sales & office	20.8%
Natural resources & construction	9.3%
Production & transportation	26.5%

Employment type

Type	%
Private sector	82.6%
Government	12.1%
Self-employed	5.3%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	82.3%
Carpool	7.0%
Public transit	0.0%
Walk	1.2%
Other means	2.4%
Avg commute (minutes)	22.3

Poverty

All people 9.9%

Under 18 years 11.5%

18 and over 9.4%

Married-couple families 2.9%

Female-led households 23.6%

Income support

Source	% of households
Social Security	37.2%
Retirement income	26.6%
Supplemental Security	3.8%
Cash public assistance	1.9%
Food stamps / SNAP	11.4%

Health indicators

Condition	%
High blood pressure	34.2%
High cholesterol	33.7%
Heart disease	7.0%
Stroke	3.1%
Asthma	9.3%
Arthritis	26.4%
Kidney disease	2.9%
Pulmonary disease	6.9%
Cancer	7.5%

Behavior / access	%
Binge drinking	20.6%
No physical activity	24.0%
Less than 7 hrs sleep	31.7%
Fair or poor health	12.6%
Poor mental health	13.1%
Poor physical health	9.8%
No health insurance	9.2%
Visited doctor (checkup)	76.1%
Visited dentist	71.9%
Cholesterol screening	89.0%
Teeth loss	12.3%

Veterans & disability

Veterans	Count	%
Civilian veterans	970	10.3%

Disability	%
Any disability	18.6%
Under 18	3.4%
18–64 years	15.7%
65 and over	42.5%

Health insurance coverage

Type	%
Private insurance	71.2%
Public insurance	43.9%
Uninsured under 19	2.5%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	11,600	96.0%
Spanish	89	0.8%
Other Indo-European	58	0.5%
Asian & Pacific Islander	31	0.3%
Other languages	0	0.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	11,911	98.6%
Born in same state	11,882	98.3%
Born in different state	9,327	77.2%
Foreign born	29	0.2%
Naturalized citizen	175	1.4%
Not a US citizen	133	76.0%

Ancestry

Ancestry	Count	%
Italian	1,586	13.1%
French	1,558	12.9%
English	1,012	8.4%
Arab	984	8.1%

Ancestry	Count	%
Polish	530	4.4%
Dutch	47	0.4%
Irish	9	0.1%

Technology access

Metric	% of households
Computer access	42.4%
Internet access	89.1%

Source: U.S. Census Bureau, American Community Survey 2025 estimates.

Frequently asked questions

What is the ZIP code for Knoxville, IA?

Knoxville, IA has one ZIP code: 50138.

What is the main ZIP code for Knoxville, IA?

The primary ZIP code for Knoxville, IA is 50138. The city uses area code 641 for phone service.

What county is Knoxville, IA in?

Knoxville is located in Marion County, Iowa.

How many ZIP codes are in Knoxville, IA?

Knoxville, IA has 1 ZIP code.

What is the ZIP code for downtown Knoxville and the historic town square area?

Downtown Knoxville and the Marion County courthouse square are located in ZIP code 50138, which serves as the central business and civic district of the city.

What ZIP code should I use for mailing addresses to businesses in Knoxville's main commercial district?

All mailing addresses in Knoxville, Iowa use ZIP code 50138, as it is the sole ZIP code serving the entire city.