The crime of assault varies from state to state (and under federal law), but is generally defined as intentionally putting another person in reasonable apprehension or fear of an imminent (immediate) harmful or offensive contact. The crime of assault may be committed even if there is no physical contact, as the criminal physical contact constitutes the separate crime of battery.

In Kentucky, assault is defined under Kentucky Revised Statutes (KRS) and is categorized into different degrees based on the severity of the offense. Assault in the first degree (KRS 508.010) involves intentional serious physical injury and is a Class B felony. Assault in the second degree (KRS 508.020) includes intentional serious physical injury with a deadly weapon or dangerous instrument, or intentional injury by means of a deadly weapon or dangerous instrument, and is a Class C felony. Assault in the third degree (KRS 508.025) typically involves assault of certain protected professionals such as state employees or utility workers and is a Class D felony. Assault in the fourth degree (KRS 508.030) concerns intentionally or wantonly causing physical injury to another, or with recklessness causing physical injury with a deadly weapon or dangerous instrument, and is a Class A misdemeanor. Kentucky law distinguishes assault from battery, with battery generally referring to the actual physical contact, which may be prosecuted under different statutes. It is important to note that the mere apprehension of harm can be sufficient for an assault charge in Kentucky, even if no physical contact occurs.