A State Senator is a member of a state Senate, the upper legislative chamber in the government of a U.S. state.

There are typically fewer state senators than there are members of a state House of Representatives. In the past, this meant that senators represented various regions within a state, regardless of the population, as a way of balancing the power of the House of Representatives which was apportioned according to population. But in 1963, the Supreme Court of the United States ruled that state legislatures must apportion seats in both houses according to population.

Nebraska is the only state that has a unicameral form of government with only one legislative chamber. Although this chamber is essentially a state House of Representatives, these legislators are called "state senators."