Steven J. Santarsiero is an American attorney and politician. A member of the Democratic Party, he has represented the 10th District in the Pennsylvania State Senate since 2019. Santarsiero previously served in the Pennsylvania House of Representatives, representing the 31st District between 2009 and 2016.

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.