Robert Patrick Casey Jr., commonly known as Bob Casey or Bob Casey Jr., is an American lawyer and politician who served as the senior United States Senator from Pennsylvania from January 2007 to 2025. A member of the Democratic Party, he represented Pennsylvania after defeating Republican Rick Santorum in the 2006 election. He was reelected in 2012 and 2018 but lost a competitive re-election bid in 2024 to Republican Dave McCormick, ending his Senate service in 2025.

Casey is a member of a prominent Pennsylvania political family, being the son of former two-term Governor Robert P. Casey Sr. (1932–2000), who served from 1987 to 1995, and Ellen Harding Casey. His father also served as a state senator (1963–1967) and Auditor General (1969–1977). The Casey family includes eight children, among them Robert Jr., Patrick (former state treasurer), and Matt (former congressman).

Born on April 13, 1960, in Scranton, Pennsylvania, Casey earned a Bachelor of Arts from The Catholic University of America in 1982 and a Juris Doctor from the University of Pennsylvania Law School in 1988. A practicing Catholic from a prominent Catholic political family, he is known for moderate positions on social issues, notably as a pro-life Democrat reflecting his father's views, while supporting gun control, labor rights, and environmental protection.

Prior to his Senate tenure, Casey served as Pennsylvania Auditor General from 1997 to 2005 and as State Treasurer from 2005 to 2007, focusing on fiscal oversight and consumer protection. He worked as a consumer advocate and attorney and ran unsuccessfully for state treasurer in 1996 and 2000.

During his Senate career, Casey focused on economic issues affecting working-class Pennsylvanians, such as manufacturing jobs, healthcare access, education funding, veterans' affairs, and health care. He served on the Finance, Health, Education, Labor and Pensions, and Special Committee on Aging committees. He was a key figure in bipartisan efforts, including legislation addressing the opioid crisis and infrastructure investment.

Casey maintained residences in Scranton and Washington, D.C., with deep roots in Pennsylvania's anthracite coal region, which influenced his focus on Rust Belt concerns. Throughout his career, he was known for integrity and bipartisanship but faced criticism from progressive Democrats for his conservative social views. Married to Terese Foppiano Casey since 1985, they have five children. Post-Senate, he continues to advocate for policies addressing economic inequality and community revitalization.