Princeton plays a significant role in New Jersey's political landscape, being located in the 12th Congressional District and part of the 16th state legislative district. For the 118th United States Congress, the district is represented by Bonnie Watson Coleman (D), who hails from Ewing Township. At the federal level, New Jersey's Senate seats are occupied by Cory Booker (D, Newark), whose term ends in 2027, and George Helmy (D, Mountain Lakes), whose term concludes in 2024.

In the 2024-2025 legislative session, the 16th legislative district is represented in the New Jersey Senate by Andrew Zwicker (D, South Brunswick). In the General Assembly, the district is served by Mitchelle Drulis (D, East Amwell Township) and Roy Freiman (D, Hillsborough Township), all working to address local and state issues.

At the county level, Mercer County is governed by a County Executive, who manages day-to-day operations, and a seven-member Board of County Commissioners that establishes legislative policies. All officials are elected at-large through partisan elections. The County Executive, currently Daniel R. Benson (D, Hamilton Township), is serving a four-year term that ends on December 31, 2027.

The Board of County Commissioners is composed of:

• Lucylle R. S. Walter (D, Ewing Township, 2026, Chair)
• John A. Cimino (D, Hamilton Township, 2026)
• Samuel T. Frisby Sr. (D, Trenton, 2024)
• Cathleen M. Lewis (D, Lawrence Township, 2025)
• Kristin L. McLaughlin (D, Hopewell Township, 2024, Vice Chair)
• Nina D. Melker (D, Hamilton Township, 2025)
• Terrance Stokes (D, Ewing Township, 2024)

In addition to the commissioners, Mercer County is supported by constitutional officers, including Clerk Paula Sollami-Covello (D, Lawrence Township, 2025), Sheriff John A. Kemler (D, Hamilton Township, 2026), and Surrogate Diane Gerofsky (D, Lawrence Township, 2026).

This structure of representation ensures that the needs and interests of Princeton and its residents are voiced at all levels of government, contributing to the community's overall governance and policy-making processes.