- Founded: 1901 (charter American League member)
- Formerly known as: Philadelphia Athletics, 1901-1954. Kansas City Athletics, 1955-1966. The team is sometimes called simply the "A's".
- Home ballpark: Network Associates Coliseum, Oakland
- Uniform colors: Green, White and Gold
- Logo design: a stylized capital "A". The team also occasionally uses a white elephant logo.
- American League pennants won: 1901, 1905, 1910, 1911, 1913, 1914, 1929, 1930, 1931, 1972, 1973, 1974, 1988, 1989, 1990.
The Philadelphia years (1901-1954)
- The "White Elephants: Connie Mack, the Lajoie scandal, early success
- The $100,000 Infield: Baker, Barry, Collins, McInnis; dominance, 1910-1913; upset by Miracle Braves in 1914; dismantling of the team and subsequent cellar-dwelling.
- 1928-1932: Rebuilding of team in 1920s. Cochrane, Grove, Foxx, Simmons, others
The Kansas City years (1955-1966)
- During the Kansas City years, the team generally did not draw well or do well. Kansas City was involved in so many bad trades with the Yankees (in which they gave up Roger Maris, Bob Cerv, and others, and got little in return) that they were jokingly considered to be a Yankee farm club.
The Oakland years (1967 to present)
- Charlie Finley and the "Swingin' A's: Fingers, Hunter, Jackson. Colorful uniforms. Mustaches return to baseball in 1972.
- The Bash Brothers: McGwire, Canseco, Stewart, Eck.
Players of note
- Baseball Hall of Famers: Frank Baker, Albert Bender, Eddie Collins, Rollie Fingers, Jimmie Foxx, Lefty Grove, Catfish Hunter, Reggie Jackson, Eddie Plank, Al Simmons
- Current stars: Jason Giambi, Tim Hudson
- Not to be forgotten: Dennis Eckersley, Dave Stewart, Bob Welch (AL Cy Young Award, 1990).
- Retired numbers: #27 Catfish Hunter, #34 Rollie Fingers, #42 Jackie Robinson