Providence County is the most populous county in the U.S. state of Rhode Island. As of the 2020 census, the county's population was 660,741, or 60.2% of the state's population. Providence County contains the city of Providence, the state capital of Rhode Island and the county's (and state's) most populous city, with an estimated 190,934 residents in 2020. Providence County is included in the Providence-Warwick, RI-MA Metropolitan Statistical Area, which in turn constitutes a portion of the greater Boston-Worcester-Providence, MA-RI-NH-CT Combined Statistical Area. As of 2010, the center of population in Rhode Island is located in Providence County, in the city of Cranston.

Providence County was constituted on June 22, 1703, as the County of Providence Plantations. It consisted of five towns, namely Providence, Warwick, Westerly, Kingstown, and Greenwich and encompassed territory in present-day Kent and Washington counties. Washington County was split off as King's County in 1729, while Kent County was split off in 1750. The town of Cumberland was acquired from Massachusetts and added to Providence County in 1746–47, and the towns of East Providence and Pawtucket were made part of Providence County when the final border with Massachusetts was settled in 1862.

County government in Rhode Island was abolished in 1842. Providence County, like other counties in Rhode Island, has no governmental functions (other than as court administrative and sheriff corrections boundaries which are part of state government).

According to the U.S. Census Bureau, the county has a total area of 436 square miles (1,130 km), of which 410 square miles (1,100 km) is land and 26 square miles (67 km) (6.0%) is water. It is the largest of Rhode Island's five counties by land area, but it's the smallest county in the United States that is a state's largest county. The county is drained by the Blackstone River, which runs partly along the east border, the Woonasquatucket River in the central part of the county, joining with the smaller Moshassuck River in downtown Providence, and the Pawtuxet, which forms a portion of the southeastern boundary of the county. The Pawtuxet is dammed in the western part of the county to form the Scituate Reservoir, which supplies drinking water for Providence and surrounding communities.

The highest natural point in the county and the state of Rhode Island is Jerimoth Hill at 812 feet (247 m). Sea level is the lowest point.

• Norfolk County, Massachusetts - northeast
• Bristol County, Massachusetts - east
• Bristol County - southeast
• Kent County - south
• Windham County, Connecticut - west
• Worcester County, Massachusetts - northwest

• Blackstone River Valley National Historical Park (part)
• Roger Williams National Memorial

Historical population

Census	Pop.	Note	%±
1790	24,376		—
1800	25,854		6.1%
1810	30,869		19.4%
1820	35,736		15.8%
1830	47,018		31.6%
1840	58,073		23.5%
1850	87,526		50.7%
1860	107,799		23.2%
1870	149,190		38.4%
1880	197,874		32.6%
1890	255,123		28.9%
1900	328,683		28.8%
1910	424,353		29.1%
1920	475,190		12.0%
1930	540,016		13.6%
1940	550,298		1.9%
1950	574,973		4.5%
1960	568,778		−1.1%
1970	580,261		2.0%
1980	571,349		−1.5%
1990	596,270		4.4%
2000	621,602		4.2%
2010	626,667		0.8%
2020	660,741		5.4%
U.S. Decennial Census 1790-1960 1900-1990 1990-2000 2010-2019

As of the census of 2000, there were 621,602 people, 239,936 households, and 152,839 families living in the county. The population density was 1,504 inhabitants per square mile (581/km). There were 253,214 housing units at an average density of 613 per square mile (237/km). The racial makeup of the county was 78.38% White, 6.55% Black or African American, 0.51% Native American, 2.90% Asian, 0.07% Pacific Islander, 8.02% from other races, and 3.58% from two or more races. 13.39% of the population were Hispanic or Latino of any race. 19.0% were of Italian, 10.9% Irish, 8.1% French, 7.7% Portuguese, 7.2% French Canadian and 5.8% English ancestry according to Census 2000. 72.7% spoke English, 13.4% Spanish, 4.9% Portuguese, 2.5% French and 1.6% Italian as their first language.

There were 239,936 households, out of which 30.70% had children under the age of 18 living with them, 44.50% were married couples living together, 14.90% had a female householder with no husband present, and 36.30% were non-families. 29.80% of all households were made up of individuals, and 11.90% had someone living alone who was 65 years of age or older. The average household size was 2.48 and the average family size was 3.11.

In the county, the population was spread out, with 24.00% under the age of 18, 11.10% from 18 to 24, 29.80% from 25 to 44, 20.50% from 45 to 64, and 14.60% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 91.80 males. For every 100 females age 18 and over, there were 87.90 males.

The median income for a household in the county was $36,950, and the median income for a family was $46,694. Males had a median income of $35,336 versus $26,322 for females. The per capita income for the county was $19,255. About 11.90% of families and 15.50% of the population were below the poverty line, including 22.30% of those under age 18 and 12.70% of those age 65 or over.

Providence County is 71% Catholic, making it among the most Catholic counties in the country.

As of the 2010 United States census, there were 626,667 people, 241,717 households, and 149,691 families living in the county. The population density was 1,530.3 inhabitants per square mile (590.9/km). There were 264,835 housing units at an average density of 646.7 per square mile (249.7/km). The racial makeup of the county was 73.4% white, 8.5% black or African American, 3.7% Asian, 0.7% American Indian, 0.1% Pacific islander, 9.6% from other races, and 4.2% from two or more races. Those of Hispanic or Latino origin made up 18.8% of the population. The largest ancestry groups were:

• 18.5% Italian
• 15.8% Irish
• 12.3% French
• 9.4% English
• 8.6% Portuguese
• 5.4% French Canadian
• 5.4% Dominican
• 4.9% Puerto Rican
• 4.3% Cape Verdean
• 4.2% German
• 3.8% Polish
• 2.9% Guatemalan
• 1.7% Scottish
• 1.6% American
• 1.2% Swedish
• 1.2% Colombian
• 1.1% Mexican
• 1.0% Scotch-Irish
• 1.0% Arab

Of the 241,717 households, 31.4% had children under the age of 18 living with them, 40.8% were married couples living together, 15.8% had a female householder with no husband present, 38.1% were non-families, and 30.2% of all households were made up of individuals. The average household size was 2.48 and the average family size was 3.11. The median age was 37.0 years.

The median income for a household in the county was $48,500 and the median income for a family was $61,265. Males had a median income of $44,964 versus $36,447 for females. The per capita income for the county was $25,169. About 11.6% of families and 15.4% of the population were below the poverty line, including 22.1% of those under age 18 and 11.5% of those age 65 or over.

• Central Falls
• Cranston
• East Providence
• Pawtucket
• Providence (traditional county seat)
• Woonsocket

As an urban county in the heavily liberal region of New England, Providence County is a Democratic stronghold. Richard Nixon is the last Republican presidential candidate to have won the county, doing so in his 1972 landslide. Even then, Nixon only carried it by a very narrow margin.

United States presidential election results for Providence County, Rhode Island

Year	Republican / Whig		Democratic		Third party(ies)
	No.	%	No.	%	No.	%
2024	112,443	41.70%	150,102	55.66%	7,134	2.65%
2020	102,551	37.61%	165,012	60.52%	5,104	1.87%
2016	90,882	36.58%	142,899	57.51%	14,693	5.91%
2012	75,785	31.61%	159,520	66.53%	4,481	1.87%
2008	81,010	31.94%	167,442	66.02%	5,178	2.04%
2004	82,337	35.59%	144,811	62.60%	4,176	1.81%
2000	61,378	28.12%	142,469	65.26%	14,461	6.62%
1996	49,901	23.52%	134,866	63.58%	27,355	12.90%
1992	69,579	27.45%	125,358	49.46%	58,504	23.08%
1988	94,248	40.77%	135,927	58.80%	984	0.43%
1984	116,024	48.16%	124,109	51.52%	765	0.32%
1980	86,467	34.88%	126,808	51.15%	34,652	13.98%
1976	103,976	41.62%	144,805	57.96%	1,036	0.41%
1972	129,418	49.94%	129,232	49.87%	506	0.20%
1968	70,320	28.11%	169,246	67.64%	10,633	4.25%
1964	43,432	16.52%	219,465	83.48%	0	0.00%
1960	91,028	32.51%	189,014	67.49%	1	0.00%
1956	153,860	55.80%	121,861	44.20%	0	0.00%
1952	146,197	48.09%	157,592	51.84%	219	0.07%
1948	93,867	38.20%	149,254	60.73%	2,627	1.07%
1944	87,190	38.80%	137,216	61.06%	321	0.14%
1940	99,434	40.60%	145,236	59.30%	251	0.10%
1936	88,492	37.17%	131,218	55.12%	18,370	7.72%
1932	84,397	40.86%	118,546	57.40%	3,601	1.74%
1928	85,884	46.77%	97,185	52.92%	568	0.31%
1924	92,464	57.24%	62,336	38.59%	6,750	4.18%
1920	79,558	61.30%	45,859	35.33%	4,374	3.37%
1916	32,406	49.18%	31,314	47.52%	2,172	3.30%
1912	19,695	33.72%	23,127	39.59%	15,587	26.69%
1908	32,037	59.58%	18,880	35.11%	2,854	5.31%
1904	30,295	59.76%	18,557	36.60%	1,846	3.64%
1900	24,194	58.03%	15,223	36.51%	2,274	5.45%
1896	26,844	66.58%	11,644	28.88%	1,832	4.54%
1892	18,695	49.16%	18,203	47.86%	1,134	2.98%
1888	14,207	51.74%	12,440	45.30%	812	2.96%
1884	12,387	57.08%	8,491	39.13%	824	3.80%
1880	11,316	61.14%	6,975	37.69%	217	1.17%
1844	3,752	54.03%	3,192	45.97%	0	0.00%

School districts include

K-12:

• Burrillville School District
• Central Falls School District
• Cranston School District
• Cumberland School District
• East Providence School District
• Johnston School District
• Lincoln School District
• North Providence School District
• North Smithfield School District
• Pawtucket School District
• Providence School District
• Scituate School District
• Smithfield School District
• Woonsocket School District

Secondary:

• Foster-Glocester Regional School District

Elementary:

• Foster Elementary School District
• Glocester Elementary School District

There is a state-operated school: Rhode Island School for the Deaf.

• National Register of Historic Places listings in Providence County, Rhode Island