[21] Belvidere was incorporated as a town by an act of the New Jersey Legislature on April 7, 1845, from portions of Oxford Township, based on the results of a referendum held that day.

[1][2] Dildine Island is located in the Delaware River, approximately 4 miles (6.4 km) north of Belvidere.

[24][25][26] The 2010 United States census counted 2,681 people, 1,054 households, and 682 families in the town.

Of all households, 28.7% were made up of individuals and 10.6% had someone living alone who was 65 years of age or older.

28.5% of all households were made up of individuals, and 11.1% had someone living alone who was 65 years of age or older.

[39][37] A large site of DSM-Firmenich Nutritional Products that includes 250,000 square feet (23,000 m2) of facilities in the town, manufacturing products including arachidonic acid and beta-carotene by fermentation processes, is located on the town's border with White Township.

A mayor is elected directly by the voters to a four-year term of office.

[6][42] As of 2022[update], the Mayor of Belvidere is Republican Kathy B Miers, whose term of office ends December 31, 2023.

Members of the Town Council are Council President Laurel Napolitani (R, 2023), Glen E. Matlock (R, 2022; elected to serve an unexpired term), Kathleen Miers (R, 2023), Donald Mitchell (R, 2022), Joseph Roth (R, 2024) and Adam Zmigrodski (R, 2024).

[45][47] In March 2015, the town council selected Timothy Petre from three candidates nominated by the Republican municipal committee to fill the seat expiring in December 2017 that had been held by William J. Murphy until he resigned from office.

[53] For the 119th United States Congress, New Jersey's 7th congressional district is represented by Thomas Kean Jr. (R, Westfield).

[54] New Jersey is represented in the United States Senate by Democrats Cory Booker (Newark, term ends 2027) and Andy Kim (Moorestown, term ends 2031).

[55] For the 2024-2025 session, the 23rd legislative district of the New Jersey Legislature is represented in the State Senate by Doug Steinhardt (R, Lopatcong Township) and in the General Assembly by John DiMaio (R, Hackettstown) and Erik Peterson (R, Franklin Township).

[60][61] Constitutional officers of Warren County are: Clerk Holly Mackey (R, Alpha; 2027),[62][63] Sheriff James McDonald Sr. (R, Phillipsburg; 2025)[64][65] and Surrogate Michael J. Doherty (R, Washington; 2025).

[69] Among the town's 2010 Census population, 62.9% (vs. 62.3% in Warren County) were registered to vote, including 84.3% of those ages 18 and over (vs. 81.5% countywide).

[78] The Belvidere School District serves students in pre-kindergarten through twelfth grade.