William Richard Keating is an American lawyer and politician serving as the U.S. representative for Massachusetts's 9th congressional district since 2013. A member of the Democratic Party, he first entered Congress in 2011, representing Massachusetts's 10th congressional district until redistricting. Keating's district includes Cape Cod and most of the South Coast. He raised his profile advocating for criminal justice issues in both houses of the Massachusetts General Court from 1977 to 1999 before becoming district attorney of Norfolk County, where he served three terms before being elected to Congress.

Massachusetts's 9th congressional district is located in eastern Massachusetts. It is represented by Democrat William R. Keating. With a Cook Partisan Voting Index rating of D+6, it is the least Democratic district in Massachusetts, a state with an all-Democratic congressional delegation.