The Pennsylvania State Senate is the upper house of the Pennsylvania General Assembly, the Pennsylvania state legislature. The State Senate meets in the State Capitol building in Harrisburg. Senators are elected for four-year terms, staggered every two years such that half of the seats are contested at each election. Even numbered seats and odd numbered seats are contested in separate election years. The president pro tempore of the Senate becomes the lieutenant governor of Pennsylvania in the event of the sitting lieutenant governor's removal, resignation or death. In this case the president pro tempore and lieutenant governor would be the same person. The Pennsylvania Senate has been meeting since 1791.

The Pennsylvania General Assembly is the legislature of the U.S. commonwealth of Pennsylvania. The legislature convenes in the State Capitol building in Harrisburg. In colonial times (1682–1776), the legislature was known as the Pennsylvania Provincial Assembly and was unicameral. Since the Constitution of 1776, the legislature has been known as the General Assembly. The General Assembly became a bicameral legislature in 1791. As of 2024, it is the only state legislature in the country in which Democrats and Republicans each control one chamber.