According to the United States Census Bureau, the township had a total area of 18.049 square miles (46.748 km2), including 17.962 square miles (46.522 km2) of land and 0.087 square miles (0.226 km2) of water (0.48%).
Unincorporated communities, localities and place names located partially or completely within the township include Branchville Junction, Harmonyvale, Hopkins Corner, Warbasse and Warbasse Junction.
The 2010 United States Census counted 2,538 people, 875 households, and 721 families residing in the township. The population density was 141.3 per square mile (54.6/km2). The township contained 919 housing units at an average density of 51.2 per square mile (19.8/km2). The racial makeup of the township was 95.43% (2,422) White, 1.58% (40) Black or African American, 0.00% (0) Native American, 0.75% (19) Asian, 0.00% (0) Pacific Islander, 0.63% (16) from other races, and 1.62% (41) from two or more races. Hispanics or Latinos of any race were 5.08% (129) of the population.
Out of a total of 875 households, 34.2% had children under the age of 18 living with them, 69.6% were married couples living together, 8.9% had a female householder with no husband present, and 17.6% were non-families. 13.1% of all households were made up of individuals, and 4.8% had someone living alone who was 65 years of age or older. The average household size was 2.85 and the average family size was 3.12.
In the township, 23.4% of the population were under the age of 18, 7.9% from 18 to 24, 20.8% from 25 to 44, 35.1% from 45 to 64, and 12.8% who were 65 years of age or older. The median age was 43.7 years. For every 100 females the census counted 95.4 males, but for 100 females at least 18 years old, it was 97.5 males.
The Census Bureau's 2006-2010 American Community Survey showed that (in 2010 inflation-adjusted dollars) median household income was $96,369 (with a margin of error of +/- $10,553) and the median family income was $98,750 (+/- $11,241). Males had a median income of $71,607 (+/- $22,034) versus $56,964 (+/- $13,270) for females. The per capita income for the borough was $34,364 (+/- $3,922). About 6.4% of families and 8.0% of the population were below the poverty line, including 12.7% of those under age 18 and 0.0% of those age 65 or over.
As of the 2000 United States Census there were 2,300 people, 771 households, and 647 families residing in the township. The population density was 127.6 people per square mile (49.3/km2). There were 799 housing units at an average density of 44.3 per square mile (17.1/km2). The racial makeup of the township was 97.04% White, 1.04% African American, 0.09% Native American, 0.78% Asian, 0.35% from other races, and 0.70% from two or more races. Hispanic or Latino of any race were 2.35% of the population.
There were 771 households out of which 38.1% had children under the age of 18 living with them, 73.4% were married couples living together, 7.5% had a female householder with no husband present, and 16.0% were non-families. 12.1% of all households were made up of individuals and 3.6% had someone living alone who was 65 years of age or older. The average household size was 2.95 and the average family size was 3.20.
In the township the population was spread out with 27.4% under the age of 18, 5.3% from 18 to 24, 29.5% from 25 to 44, 28.6% from 45 to 64, and 9.3% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 100.7 males. For every 100 females age 18 and over, there were 97.7 males.
The median income for a household in the township was $82,805, and the median income for a family was $87,650. Males had a median income of $61,307 versus $38,816 for females. The per capita income for the township was $30,491. About 1.2% of families and 3.7% of the population were below the poverty line, including 2.0% of those under age 18 and 2.3% of those age 65 or over.
Lafayette Township is governed under the Township form of government. The five-member Township Committee is elected directly by the voters at-large in partisan elections to serve three-year terms of office on a staggered basis, with either one or two seats coming up for election each year as part of the November general election in a three-year cycle. At an annual reorganization meeting, the Township Committee selects one of its members to serve as Mayor.
As of 2016, members of the Lafayette Township Committee are Alan Henderson (R, term on township committee ends December 31, 2017; term as mayor ends 2016), Gregory Corcoran (R, term on committee ends 2017; term as deputy mayor ends 2016), Richard Bruning (R, 2016), John D'Angeli (R, 2018) and Richard Hughes (R, 2016).
Lafayette Township is located in the 5th Congressional District and is part of New Jersey's 24th state legislative district.
New Jersey's Fifth Congressional District is represented by Josh Gottheimer (D, Wyckoff). New Jersey is represented in the United States Senate by Cory Booker (D, Newark, term ends 2021) and Bob Menendez (D, Paramus, 2019).
For the 2016–2017 session (Senate, General Assembly), the 24th Legislative District of the New Jersey Legislature is represented in the State Senate by Steve Oroho (R, Franklin) and in the General Assembly by Parker Space (R, Wantage Township) and Gail Phoebus (R, Andover Township). The Governor of New Jersey is Chris Christie (R, Mendham Township). The Lieutenant Governor of New Jersey is Kim Guadagno (R, Monmouth Beach).
Sussex County is governed by a Board of Chosen Freeholders whose five members are elected at-large in partisan elections on a staggered basis, with either one or two seats coming up for election each year. At an annual reorganization meeting held in the beginning of January, the board selects a Freeholder Director and Deputy Director from among its members, with day-to-day supervision of the operation of the county delegated to a County Administrator. As of 2014, Sussex County's Freeholders are Freeholder Director Richard Vohden (R, Green Township, 2016), Deputy Director Dennis J. Mudrick (R, Sparta Township, 2015), Phillip R. Crabb (R, Franklin, 2014), George Graham (R, Stanhope, 2016) and Gail Phoebus (R, Andover Township, 2015). Graham was chosen in April 2013 to fill the seat vacated by Parker Space, who had been chosen to fill a vacancy in the New Jersey General Assembly. Constitutional officers elected on a countywide basis are County Clerk Jeff Parrott (R, 2016), Sheriff Michael F. Strada (R, 2016) and Surrogate Gary R. Chiusano (R, filling the vacancy after the resignation of Nancy Fitzgibbons). The County Administrator is John Eskilson.
As of March 23, 2011, there were a total of 1,738 registered voters in Lafayette Township, of which 228 (13.1% vs. 16.5% countywide) were registered as Democrats, 781 (44.9% vs. 39.3%) were registered as Republicans and 727 (41.8% vs. 44.1%) were registered as Unaffiliated. There were 2 voters registered to other parties. Among the township's 2010 Census population, 68.5% (vs. 65.8% in Sussex County) were registered to vote, including 89.4% of those ages 18 and over (vs. 86.5% countywide).
In the 2012 presidential election, Republican Mitt Romney received 867 votes (65.7% vs. 59.4% countywide), ahead of Democrat Barack Obama with 431 votes (32.7% vs. 38.2%) and other candidates with 18 votes (1.4% vs. 2.1%), among the 1,319 ballots cast by the township's 1,815 registered voters, for a turnout of 72.7% (vs. 68.3% in Sussex County). In the 2008 presidential election, Republican John McCain received 921 votes (67.3% vs. 59.2% countywide), ahead of Democrat Barack Obama with 417 votes (30.5% vs. 38.7%) and other candidates with 18 votes (1.3% vs. 1.5%), among the 1,368 ballots cast by the township's 1,740 registered voters, for a turnout of 78.6% (vs. 76.9% in Sussex County). In the 2004 presidential election, Republican George W. Bush received 883 votes (67.4% vs. 63.9% countywide), ahead of Democrat John Kerry with 404 votes (30.8% vs. 34.4%) and other candidates with 18 votes (1.4% vs. 1.3%), among the 1,311 ballots cast by the township's 1,583 registered voters, for a turnout of 82.8% (vs. 77.7% in the whole county).
In the 2013 gubernatorial election, Republican Chris Christie received 76.5% of the vote (646 cast), ahead of Democrat Barbara Buono with 20.4% (172 votes), and other candidates with 3.1% (26 votes), among the 855 ballots cast by the township's 1,824 registered voters (11 ballots were spoiled), for a turnout of 46.9%. In the 2009 gubernatorial election, Republican Chris Christie received 635 votes (66.2% vs. 63.3% countywide), ahead of Democrat Jon Corzine with 214 votes (22.3% vs. 25.7%), Independent Chris Daggett with 94 votes (9.8% vs. 9.1%) and other candidates with 14 votes (1.5% vs. 1.3%), among the 959 ballots cast by the township's 1,702 registered voters, yielding a 56.3% turnout (vs. 52.3% in the county).
Public school students in pre-kindergarten through eighth grade attend the Lafayette Township School District. As of the 2014-15 school year, the district and its one school had an enrollment of 355 students and 26.1 classroom teachers (on an FTE basis), for a student–teacher ratio of 13.6:1.
For ninth through twelfth grades, public school students attend High Point Regional High School, which also serves students from Branchville, Frankford Township, Montague Township, Sussex Borough and Wantage Township (where the school is located). As of the 2014-15 school year, the high school had an enrollment of 1,002 students and 94.3 classroom teachers (on an FTE basis), for a student–teacher ratio of 10.6:1.
As of May 2010, the township had a total of 46.27 miles (74.46 km) of roadways, of which 29.91 miles (48.14 km) were maintained by the municipality, 10.24 miles (16.48 km) by Sussex County and 6.12 miles (9.85 km) by the New Jersey Department of Transportation.
People who were born in, residents of, or otherwise closely associated with Lafayette Township include:Andy Albeck (1921-2010), movie executive who served as president and chief executive of United Artists and operated the award-winning Albeck Family Christmas Tree farm in Lafayette Township.
Cleve Backster (1924-2013), interrogation specialist for the Central Intelligence Agency, best known for his 1960s experiments with plants using a polygraph which led to his theory of "primary perception" where he claimed that plants "feel pain" and have extrasensory perception.
Andrew J. Rogers (1828-1900), lawyer, teacher, clerk, police commissioner and Democratic Party politician who represented New Jersey's 4th congressional district in the United States House of Representatives from 1863-1867.
Jay Nelson Tuck (1916-1985), journalist, television critic who served as president of The Newspaper Guild from 1950 to 1952.