A lieutenant governor, lieutenant-governor, or vice governor is a high officer of state, whose precise role and rank vary by jurisdiction. Often a lieutenant governor is the deputy, or lieutenant, to or ranked under a governor — a "second-in-command", rather like deputy governor. In Canadian provinces and in the Dutch Caribbean, the lieutenant governor is the representative of the monarch in that jurisdiction, and thus outranks the head of government but for practical purposes has virtually no power.

In India, lieutenant governors are in charge of special administrative divisions in that country.

In the United States, lieutenant governors are usually second-in-command to a state governor, and the actual power held by the lieutenant governor varies greatly from state to state. The lieutenant governor is often first in line of succession to the governorship, and acts as governor when the governor leaves the state or is unable to serve. Also, the lieutenant governor is often the president of the state senate.

In Argentina, lieutenant governors are called "vice governors" and are modeled after the U.S. lieutenant governors, since as their U.S. counterpart the vice governors are the second-in-command to a provincial governor, and are the first in the gubernatorial line of succession. Also, the vice governor usually acts as the president of the provincial senate (or the provincial legislature in unicameral provinces).