Great Mills ZIP Code List — Saint Marys County, MD

There is one unique ZIP code in Great Mills, Maryland and it is 20634. Area code: 240/301.

ZIP codes

6.99

sq mi land

0.07

sq mi water

240/301

area code

Great Mills, MD ZIP code map

About Great Mills, MD

Great Mills, Maryland, is a charming community located in Saint Marys County. Known for its close-knit atmosphere and rich history, this small town offers a unique blend of rural and suburban living. It serves as a wonderful place to explore the natural beauty and local culture of Southern Maryland.

Location & geography

Great Mills sits approximately 5 miles from Leonardtown, the county seat, and is about 7 miles from California, MD. The town is characterized by its picturesque terrain, encompassing a total land area of 6.99 square miles, with a minor water area of 0.07 square miles. This beautiful location contributes to the area's appeal for outdoor enthusiasts and nature lovers.

Community & economy

The character of Great Mills is reflected in its friendly residents and small-town charm, creating a welcoming environment for newcomers. Local industries include a mix of retail and services, which help sustain the community’s economy. Daily life in Great Mills revolves around community activities, with residents enjoying local parks and events that foster strong social bonds.

Transportation

Great Mills is conveniently located near major transportation routes, including Maryland Route 249 and Maryland Route 5, facilitating easy travel to neighboring towns. The nearest airports include the St. Mary's County Regional Airport, which is just a short drive away, offering connections and services for both general aviation and commercial travel.

History

Founded in the early 18th century, Great Mills has a rich historical background, with its early economy supported by agriculture and timber. Notable events in the area’s history include its development around the regional lumber industry, which played a significant role in the town's growth. Over the years, Great Mills has evolved while maintaining its historical roots.

Did you know?

One surprising fact about Great Mills is that it is home to the historic site known as the Great Mills Trading Post, which dates back to the 1800s. Additionally, the town is near several significant battlefields from the Civil War, highlighting its importance in American history.

ZIP codes for Great Mills, MD (1)

ZIP code	City	County	Map
20634	Great Mills	Saint Marys	View map

Demographics & statistics

7,853

Population

33.1

Median age

$131,042

Median household income

$55,890

Per capita income

$327,800

Median home value

$1,505

Median monthly rent

69.1%

Home ownership

5.5%

Poverty rate

0.6%

Unemployment

2,117

Housing units

38.0%

Bachelor's or higher

Age distribution

Male Female

239

Under 5

214

323

5–9

290

346

10–14

310

329

15–19

296

178

20–24

159

798

25–34

715

684

35–44

613

460

45–54

413

322

55–59

289

232

60–64

208

161

65–74

145

75–84

85+

← Male

Female →

Age summary

Group	Count	%
Under 18	2,013	25.6%
18 and over	5,840	74.4%
65 and over	435	5.5%
Median age	33.1 years

Race & ethnicity

White 54.7%

Black or African American 32%

Two or more races 6.5%

Hispanic or Latino 2.8%

Asian 2.2%

Other race 1.8%

Group	Count	%
White	4,418	54.7%
Black or African American	2,588	32%
Two or more races	523	6.5%
Hispanic or Latino	225	2.8%
Asian	178	2.2%
Other race	146	1.8%

Household income

Under $10k 0.6%

$10k–$15k 2.4%

$15k–$25k 3.7%

$25k–$35k 1.8%

$35k–$50k 8.6%

$50k–$75k 9.7%

$75k–$100k 11.0%

$100k–$150k 20.5%

$150k–$200k 19.2%

$200k+ 22.4%

Range	% of households
Under $10k	0.6%
$10k–$15k	2.4%
$15k–$25k	3.7%
$25k–$35k	1.8%
$35k–$50k	8.6%
$50k–$75k	9.7%
$75k–$100k	11.0%
$100k–$150k	20.5%
$150k–$200k	19.2%
$200k+	22.4%
Median income	$131,042

Housing

Home values

Under $50k 7.3%

$50k–$100k 0.8%

$150k–$200k 9.3%

$200k–$300k 24.1%

$300k–$500k 47.8%

$500k–$1M 9.1%

$1M+ 1.6%

Housing overview

Metric	Value
Median home value	$327,800
Median rent / month	$1,505
Owner occupied	69.1%
Renter occupied	30.9%
Vacant	7.1%
Single-family detached	62.5%
Large apartment buildings	0.6%
Mobile homes	3.4%
Median rooms	6.5
Avg household size (owned)	3.15

Year built

Era	%
2020 or later	0.0%
2010–2019	8.2%
2000–2009	27.6%
1990–1999	34.3%
1980–1989	18.9%
1970–1979	6.6%
1960–1969	0.0%
1950–1959	1.8%
1940–1949	0.7%
1939 or earlier	1.9%

Bedrooms

Size	% of units
No bedroom (studio)	1.2%
1 bedroom	0.6%
2 bedrooms	16.8%
3 bedrooms	41.6%
4 bedrooms	31.2%
5+ bedrooms	8.7%

Vehicles per household

Vehicles	% of households
No vehicle	4.9%
1 vehicle	18.0%
2 vehicles	42.2%
3 or more	34.9%

Heating fuel

Fuel type	%
Utility gas	24.3%
Electricity	66.2%
Propane / LP gas	4.7%
Fuel oil	1.9%
Wood	0.4%
Solar	0.9%
No fuel used	1.6%

Households & families

Household type	Count	%
Married-couple family	1,297	47.0%
Cohabiting couple	159	5.8%
Male householder, no spouse	749	27.1%
Female householder, no spouse	555	20.1%
Households with children under 18	912	33.0%
Households with seniors (65+)	333	12.1%
Average household size	2.84

Marital status

Status	Male	Female
Never married	43.3%	32.8%
Married	44.4%	48.6%
Separated	3.6%	2.4%
Widowed	3.7%	4.7%
Divorced	5.1%	11.5%

Education

Less than 9th grade 1.1%

Some HS, no diploma 3.1%

HS graduate 24.8%

Some college, no degree 22.4%

Associate's degree 10.7%

Bachelor's degree 21.8%

Graduate / professional 16.1%

Metric	%
HS diploma or higher	95.8%
Bachelor's or higher	38.0%

School enrollment (ages 3–17)

Type	Count	%
Nursery / preschool	210	8.5%
Kindergarten	214	8.6%
Elementary school	920	37.1%
High school	463	18.7%
College / grad school	675	27.2%

Employment

Industry of employment

Public administration 20.1%

Education & healthcare 18.0%

Professional & management 15.5%

Retail trade 14.2%

Arts, food & hospitality 6.9%

Transportation & utilities 6.2%

Construction 5.4%

Other services 4.9%

Manufacturing 3.7%

Information 1.9%

Agriculture & mining 1.8%

Finance & real estate 1.3%

Occupation

Category	%
Management, business & arts	48.2%
Service	13.1%
Sales & office	19.3%
Natural resources & construction	7.3%
Production & transportation	12.1%

Employment type

Type	%
Private sector	59.7%
Government	37.7%
Self-employed	2.6%
Unpaid family workers	0.0%

Commute

Method	%
Drive alone	75.5%
Carpool	5.3%
Public transit	0.9%
Walk	6.2%
Other means	0.0%
Avg commute (minutes)	25.5

Poverty

All people 5.5%

Under 18 years 4.5%

18 and over 5.8%

Married-couple families 0.0%

Female-led households 28.3%

Income support

Source	% of households
Social Security	11.9%
Retirement income	23.1%
Supplemental Security	2.0%
Cash public assistance	0.0%
Food stamps / SNAP	7.1%

Health indicators

Condition	%
High blood pressure	31.8%
High cholesterol	30.5%
Heart disease	4.3%
Stroke	2.3%
Asthma	10.4%
Arthritis	21.4%
Kidney disease	2.2%
Pulmonary disease	4.9%
Cancer	4.7%

Behavior / access	%
Binge drinking	16.1%
No physical activity	21.9%
Less than 7 hrs sleep	38.3%
Fair or poor health	11.5%
Poor mental health	14.9%
Poor physical health	7.9%
No health insurance	10.7%
Visited doctor (checkup)	75.5%
Visited dentist	66.1%
Cholesterol screening	90.6%
Teeth loss	11.6%

Veterans & disability

Veterans	Count	%
Civilian veterans	1,117	19.4%

Disability	%
Any disability	8.6%
Under 18	1.8%
18–64 years	9.8%
65 and over	25.3%

Health insurance coverage

Type	%
Private insurance	84.8%
Public insurance	22.6%
Uninsured under 19	0.0%

Language & origin

Language spoken at home (age 5+)

Language	Count	%
English only	7,400	94.2%
Spanish	131	1.8%
Other Indo-European	35	0.5%
Asian & Pacific Islander	0	0.0%
Other languages	71	1.0%

Place of birth & citizenship

Origin	Count	%
Native born (US)	7,309	93.1%
Born in same state	7,054	89.8%
Born in different state	2,844	36.2%
Foreign born	255	3.2%
Naturalized citizen	544	6.9%
Not a US citizen	417	76.7%

Ancestry

Ancestry	Count	%
Italian	1,150	14.6%
French	689	8.8%
Arab	277	3.5%
Polish	92	1.2%

Ancestry	Count	%
Dutch	37	0.5%
Irish	19	0.2%
English	11	0.1%

Technology access

Metric	% of households
Computer access	35.1%
Internet access	99.1%

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

Frequently asked questions

What is the ZIP code for Great Mills, MD?

Great Mills, MD has one ZIP code: 20634.

What is the main ZIP code for Great Mills, MD?

The primary ZIP code for Great Mills, MD is 20634. The city uses area code 240 or 301 for phone service.

What county is Great Mills, MD in?

Great Mills is located in Saint Marys County, Maryland.

How many ZIP codes are in Great Mills, MD?

Great Mills, MD has 1 ZIP code.

What is the ZIP code for Great Mills in Saint Marys County, Maryland?

Great Mills, Maryland is located in ZIP code 20634, which serves the community in Saint Marys County.

If I'm mailing something to a business in Great Mills near the Great Mills High School area, what ZIP code should I use?

You should use ZIP code 20634 for any addresses in Great Mills, including the area around Great Mills High School, as this is the single ZIP code that covers the entire Great Mills community.