William Richard Keating (born September 6, 1952) 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.

Raised in Sharon, Massachusetts, Keating "took a traditional route to politics", attending Boston College and Suffolk University Law School. He was elected to the Massachusetts House of Representatives in 1976 at age 24 and went on to serve in the Massachusetts Senate from 1985 to 1999. He authored numerous bills signed into law concerning taxation, drug crime, and sentencing reform. His attempted overthrow of Senate President William M. Bulger in 1994 was a failure but boosted his local name recognition, which contributed to his success in the 1998 election for DA.

Keating followed the path of former Norfolk County District Attorney Bill Delahunt to the U.S. House of Representatives, winning election in 2010 to represent the 10th congressional district. In 2012, after redistricting drew his home in Quincy into the district of fellow incumbent Stephen Lynch, Keating chose to run in the redrawn 9th district, which combined the eastern portion of his old district with new territory on the South Coast taken from the 4th district long represented by Barney Frank. Keating has been reelected five times from this district. In the 119th Congress, he sits on the House Armed Services Committee and Foreign Affairs Committee. Much of his work has focused on domestic issues central to his district, such as the fishing industry and nuclear safety.

Keating was born in Norwood, Massachusetts, on September 6, 1952. After graduating from Sharon High School in Sharon, Massachusetts, Keating enrolled at Boston College, from which he received his Bachelor of Arts in 1974, and his Master of Business Administration in 1982. In 1985, Keating earned his Juris Doctor from Suffolk University Law School and passed the bar exam. He later became a partner at the law firm of Keating & Fishman.

In 1977, Keating was elected to the Massachusetts House of Representatives from the 19th Norfolk district, where he served for a year. He was then elected from the 8th Norfolk district, serving from 1979 to 1984. He supported George Keverian's successful 1985 effort to overthrow Thomas W. McGee as Speaker of the House. By the end of his House tenure, Keating became vice chairman of the House Criminal Justice Committee.

In 1984, State Senator Joseph F. Timilty resigned his Norfolk and Suffolk seat to pursue a career in private law, and Keating became the only major Democratic contender for the office. In the general election he faced Republican Marion Boch, who promoted a plan for dramatic cuts to legislators' pay and hours, invoking the energy of the Ronald Reagan campaign.

Keating focused his campaign on expanding resources for crime prevention and education, tailoring his message to the Boston constituency he would pick up as a senator. He was elected with about 64% of the vote.

In his first year, Keating was named Senate chairman of the joint Public Safety Committee, where he led the legislative action for a statewide seat belt law pushed by Governor Michael Dukakis. He authored a drug sentencing reform package signed into law in 1988, lowering thresholds for possession charges and establishing new minimum sentences, including a one-year minimum sentence for first-time possession of cocaine or PCP "with intent to distribute". The latter provision was widely derided by criminal justice authorities as excessively strict and vaguely worded.