The Baltimore Orioles are an American professional baseball team based in Baltimore. The Orioles compete in Major League Baseball (MLB) as a member of the American League (AL) East Division. As one of the American League's eight charter teams in 1901, the franchise spent its first year as a major league club in Milwaukee as the Milwaukee Brewers before moving to St. Louis to become the St. Louis Browns in 1902. After 52 years in St. Louis, the franchise was purchased in 1953 by a syndicate of Baltimore business and civic interests, led by attorney and civic activist Clarence Miles and Mayor Thomas D'Alesandro Jr. The team's current owner is David Rubenstein. The Orioles' home ballpark is Oriole Park at Camden Yards, which opened in 1992 in downtown Baltimore. The oriole is the official state bird of Maryland; the name has been used by several baseball clubs in the city, including another AL charter member franchise which moved to New York in 1903 and became the Yankees. Nicknames for the team include the "O's" and the "Birds".

Baltimore is the most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 census, it is the 30th-most populous city in the United States. Baltimore was designated an independent city by the Constitution of Maryland in 1851, and is currently the most populous independent city in the nation. As of the 2020 census, the population of the Baltimore metropolitan area was 2,838,327, the 20th-largest metropolitan area in the country. When combined with the larger Washington metropolitan area, the Washington–Baltimore combined statistical area (CSA) has a 2020 U.S. census population of 9,973,383, the third-largest in the country.