The Legislature is the chief policy-making body for Onondaga County. The Legislature meets on the first Tuesday of each month (other than holidays) in Regular Session. Additional Special Sessions may be called from time to time when pressing matters cannot wait for the next scheduled monthly meeting.

In discharging its responsibilities, the Legislature operates through 8 standing committees. Each standing committee oversees the work of several executive branch departments and is expected to review and study policy issues related to the subject matter under its jurisdiction. The standing committees also meet on a monthly schedule, with additional special meetings and joint meetings scheduled as needed.

The Legislature's primary annual responsibility is to review the County Executive's proposed budget, modify it (if necessary) and approve an adopted County Budget. The review is conducted by the Legislature's Ways and Means Committee during the last two weeks of September. The budget, with the committee's changes, then goes to a public hearing in early October, with a vote by the full Legislature taking place in a Budget Session in mid-October.

The Legislature consists of 19 members, each of whom is elected from a single-member district, which contained, at the time they were drawn in 2001, approximately 24,000 people. Four districts are located entirely within the City of Syracuse, 11 are located entirely outside of Syracuse and four located partly within and partly outside the City. All members are elected to two-year terms in odd-numbered years.

The Legislature is presided over by the Chairman, who is elected by the members at the first meeting of the year subsequent to an election. The Floor Leaders are announced by the respective party caucuses at the same time.