The sheriff is an elected official in a county (or independent city) responsible for keeping the peace and enforcing the law.  Sheriffs are accountable directly to the constitution of their state, the United States Constitution, statutes, and the citizens of their county. There are sheriff’s in 48 states, with two exceptions, Alaska which does not have counties and Connecticut which has no county governments.
Sheriffs are elected to four-year terms in 42 states, two-year terms in Arkansas and New Hampshire, three-year terms in New Jersey, and six-year terms in Massachusetts. In many rural areas of the United States, particularly in the South, the sheriff has traditionally been viewed as one of a given county's most influential political office-holder.

The responsibilities of sheriffs and their agencies vary considerably by county. Many sheriffs have the role of a police chief, though some lead agencies with limited law enforcement duties. Sheriffs are also often responsible for managing county jails and security at local government buildings.

An officer of a sheriff's office is typically known as a deputy sheriff, sheriff's deputy or informally as a deputy. In a small sheriff's office, the deputies are supervised directly by the sheriff. Large sheriff’s offices have several ranks in a similar manner to a police department. The actual second-in-command of the sheriff typically holds the title of chief deputy or undersheriff. In some counties, the undersheriff is the warden of the county jail or detention center.