His father-in-law was a longtime leader, including as governor, of the province of West Jersey, where Edward married.

[24] Henry Gannett attributes the borough's name to colonial governors from the Pennington family.

[40][38] Pennington Day, typically in the middle of May, is an annual event where local organizations and businesses set up booths in a street-fair style on Main Street.

The event, with origins back to 1980, features local music and a parade early in the day and festivities continuing into the afternoon.

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

[45] As of 2023[update], the mayor of Pennington is Democrat James Davy, who was elected to serve an unexpired term of office ending December 31, 2023.

Members of the Borough Council are Council President Catherine M. "Kit" Chandler (D, 2023), Katrina Angarone (D, 2025), Deborah L. Gnatt (D, 2024), Charles "Chico" Marciante (D, 2025), Nadine Stern (D, 2024) and John Valenza (D, 2023; appointed to serve an unexpired term).

[3][46][47][48][49][50][51] In February 2023, the council selected John Valenza to fill the seat that had been held by Ken Gross expiring in December 2023 that became vacant when he resigned.

[52] Katrina Angarone was selected in February 2022 from a list of three names submitted by the Democratic municipal committee to fill the seat expiring in December 2022 that had been held by Beverly Mills until her resignation from office the previous month.

[53] In June 2021, the borough council appointed former councilmember James Davy to fill the mayoral seat expiring in December 2023 that became vacant following the resignation of Joseph Lawver earlier that month.

[55] Former mayor Persichilli was first elected on November 7, 2006, to fill the vacancy left by the resignation of James Loper.

Returned to office at that same election were Democratic council members Joseph Lawver and Eileen Heinzel.

[56] James Loper, the previous elected mayor, had resigned from office effective February 1, 2006.

[57] That same procedure was repeated in December 2006, when the borough council selected Diane Zompa to fill the unexpired term left by Persichilli.

[60][61][62] For the 119th United States Congress, New Jersey's 12th congressional district is represented by Bonnie Watson Coleman (D, Ewing Township).

[67] As of 2025[update], the County Executive is Daniel R. Benson (D, Hamilton Township) whose term of office ends December 31, 2027.

[111][112] The district's board of education is comprised of nine members allocated to each of the three municipalities based on population, with Pennington assigned a single seat.

[113] Eighth grade students from all of Mercer County are eligible to apply to attend the high school programs offered by the Mercer County Technical Schools, a county-wide vocational school district that offers full-time career and technical education at its Health Sciences Academy, STEM Academy and Academy of Culinary Arts, with no tuition charged to students for attendance.

[118] Additionally, exit 73 along I-295 connects to Scotch Road North, which provides access to all of the surrounding Hopewell Township area.