Since 1915, only two "major" leagues have been in existence; and literally hundreds (if not thousands) of players have been on teams in both leagues.
During the seasons of 1914 and 1915, the Federal League operated; and Baseball history officially recognizes this as a "major" league. Scores of players -- including six future Hall of Famers -- played in this league as well as either the AL and the NL; so most likely dozens have played in three major leagues.
Likewise, a few entire TEAMS jumped from the Player's Association (1890) to the American Association, and then to the National League. Thus, some players went through three leagues in just over three years!
I doubt anyone has played in four leagues that are presently and unambiguously considered "major."
In the 2009 season, that is pitcher Ron Villone of the Washington Nationals. The Nats are his 12th team, an MLB record that he shares with Mike Morgan. 1995: San Diego Padres, Seattle Mariners
1996: San Diego Padres, Milwaukee Brewers
1997: Milwaukee Brewers
1998: Cleveland Indians
1999-2000: Cincinnati Reds
2001: Colorado Rockies, Houston Astros
2002: Pittsburgh Pirates
2003: Houston Astros
2004: Seattle Mariners
2005: Seattle Mariners, Florida Marlins
2006-2007: New York Yankees
2008: St. Louis Cardinals
2009: Washington Nationals
Ken Griffey Jr. Through games played on June 15, 2009 Griffey Jr. is the active player with the most base hits with 2714. Omar Viquel is second with 2676.
Joe Youngblood
Cal Ripkin
Hank Aaron was the last Negro League player to have a regular position in the Major League. Minnie Minoso was the last to actually play in a MLB game. (Two games for the White Sox in 1980.)
Rich Loiselle was a professional baseball player who played as a pitcher. He was active in Major League Baseball (MLB) from 1996 to 2000. Loiselle played for the Pittsburgh Pirates during the entirety of his career at the MLB level.
Omar Vizquel
Manny Ramirez is the top active non-Yankees player with the most postseason appearances with 111 games played.
None, there has never been a female player in Major League baseball.
Ken Griffey Jr. Through games played on June 15, 2009 Griffey Jr. is the active player with the most base hits with 2714. Omar Viquel is second with 2676.
Matsui
Michael Jordan almost did he played Mlb, Nba, and golf!
Yogi Berra.
Deion Sanders
derek jeeter
baseball player She played "All the way May"
Joe Youngblood
He was a Major League Baseball player.