The town is governed by a Board of Selectmen (the executive branch) who are elected every two years. The Selectmen are paid elected officials. Town departments are staffed by paid professionals while the remainder of the Town's elected officials consist of unpaid citizen volunteers.

Selectmen - The Executive Branch
The Board of Selectmen is composed of a full-time First Selectman (the chief executive) and two part-time Selectman. They are elected to serve for a term of two years. No more than two of the selectmen can be members of the same political party. The fire, police, public works, purchasing, Parks & Recreation, Law Department, and Human Relations report to the First Selectman. The Finance Department, however, is hired by, and reports to, the Board of Estimate and Taxation.

Board of Estimate and Taxation - The Town's Comptroller
Known as the BET, this group of 12 members, who are volunteers elected for a two year term, acts as the Town's comptroller. They are responsible for the oversight of the Town's financial affairs, they prepare the Town's annual budget and, (subject to approval by the RTM), they set the annual property tax rate.

Representative Town Meeting - The Legislative Body
Greenwich, like many New England towns, began by managing its affairs through a Town Meeting of all electors. The first recorded Town Meeting was held on February 5, 1664. By 1933, the town had grown so large that it had to abandon open town meetings and adopted the Representative Town Meeting (RTM), in which one person represented 100 voters. As the town grew, so did the RTM, whose size was eventually capped at 230 members, making it the largest legislature in the State of Connecticut.

The members of the RTM are elected every two years by the voters in each of the town's 12 districts. Any registered voter in town may run as a candidate in his or her district. The RTM is non-partisan. Candidates run without party identification and serve without compensation. As a result, the composition of the RTM is very egalitarian.

Each RTM district elects a member as delegate and an alternate to one of the standing committees, which oversee the operation of the town's departments. Delegates report the result of the meetings they attend at their district's monthly meeting and then after a full discussion, the members vote at the monthly RTM meeting.

These meetings are open to the public and can be addressed by anyone who wishes to share their opinion. The RTM's agenda, "The Call", is posted online. Any citizen who wishes to put an item on "The Call" may do so by giving the town clerk a petition signed by 20 voters.

The RTM reviews appointments to all the appointed boards, all the interim appropriations, labor contracts, municipal improvements, gifts to the town and, of course, BET (Board of Estimate & Taxation) and Board of Education budgets.

Independent Boards
There are a number of independent boards and commissions, which are completely volunteer and have great power in how the town runs: Alarm Appeals, Architectural Review, Board of Ethics, Board of Health, Building Code Board of Standards and Appeals, Commission on Aging, Condemnation Board, Conservation, Flood & Erosion Control, Historic District, Housing Authority, Inland Wetlands & Water Courses Agency, Nathaniel Witherell, Parks & Recreation, Planning & Zoning Appeals, and Social Services.

Candidates for board memberships on these committees are nominated by the Board of Selectmen, interviewed by the RTM Appointments Committee, and one or more of the other RTM committees, and then voted on by the RTM during its monthly meeting.