The Baltimore Orioles name had been used by various Baltimore-based baseball teams for over 6 decades before the present-day American League team took on that name in 1954. The teams were all named for the bird of the exact same name, the "Baltimore Oriole".
The current Orioles franchise began as the Milwaukee Brewers and played in the Western League beginning in 1894, the WL re-named itself the American League in 1900 and gained Major League status for the 1901 season. In an attempt to compete directly with the National League, the AL relocated the Brewers to St. Louis for 1902 to go head-to-head with the Cardinals. They took on the name "St. Louis Browns".
Wanting to relocate his team out of the rapidly-declining Sportsman's Park, Browns owner Bill Veeck tried to move the team back to Milwaukee, which was blocked by the league. He then tried to sell half his ownership and relocate to Baltimore, which again was blocked by the league. After it was becoming clear the league would not approve any move which kept Veeck as an owner he then sold his entire stock in the Browns to Baltimore brewer Jerold Hoffberger which the league approved. The Browns moved to Baltimore in time for the 1954 season.