[20] Bloomsbury was incorporated as a borough by an act of the New Jersey Legislature on March 30, 1905, from portions of Bethlehem Township.

[22] The 2010 United States census counted 870 people, 337 households, and 237 families in the borough.

Of all households, 24.0% were made up of individuals and 6.8% had someone living alone who was 65 years of age or older.

[32] As of the 2000 United States census,[15] there were 886 people, 322 households, and 252 families residing in the borough.

15.8% of all households were made up of individuals, and 5.3% had someone living alone who was 65 years of age or older.

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

[6] The borough form of government used by Bloomsbury is a "weak mayor / strong council" government in which council members act as the legislative body with the mayor presiding at meetings and voting only in the event of a tie.

The mayor can veto ordinances subject to an override by a two-thirds majority vote of the council.

[34][35] As of 2024[update], the mayor of Bloomsbury is Republican Vicky Papics, whose term of office ends December 31, 2027.

Members of the Borough Council are Todd Dangelo (R, 2025), Megan Henry (R, 2024), Scott McClaymont (R, 2025), Jaime Newman (R, 2026; appointed to serve an unfilled term of office), Chris Smith (R, 2024) and Daniel J. Smith (R, 2026).

[42][43][44] For the 119th United States Congress, New Jersey's 7th congressional district is represented by Thomas Kean Jr. (R, Westfield).

[46] 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).

At an annual reorganization meeting held each January, the commissioners select one member to serve as the board's Director and another to serve as Deputy Director, each for a one-year term.

[53][54] Constitutional officers elected on a countywide basis are Clerk Mary H. Melfi (R; Flemington, 2026),[55][56] Sheriff Fredrick W. Brown (R; Alexandria Township, 2025)[57][58] and Surrogate Heidi Rohrbach (R; Lebanon Township, 2028).

[80] Eighth grade students from all of Hunterdon County are eligible to apply to attend the high school programs offered by the Hunterdon County Vocational School District, a county-wide vocational school district that offers career and technical education at its campuses in Raritan Township and at programs sited at local high schools, with no tuition charged to students for attendance.

[87] Norfolk Southern Railway's Lehigh Line (formerly the mainline of the Lehigh Valley Railroad), runs through the southwest part of Bloomsbury along the border with Bethlehem Township on its way to Phillipsburg, New Jersey.