In MLB, for players with at least 400 at bats that was DH Adam Dunn of the Chicago White Sox at .159 (66 hits in 415 at bats).
Tony Armas of the Red Sox had the lowest batting average for an RBI leader. He had 107 RBIs and a .218 batting average.
Stan Musial had a career low of .255 batting average in the 1963 season.
In 2010, Derek Jeter finished the season with a .270 batting average, in 2011 he had a .297 average.
Reggie Jackson
The dubious honor of the lowest batting average while still qualifying for the batting title belongs to Rob Deer. In 1991, playing for the Detroit Tigers, Deer batted .179 in 539 plate appearances.
In 2011, Derek Jeter finished the season with a .297batting average.
0.299
As of the 7th game in the 2011-2012 season the phillies are in 1st in batting average batting .337
In 1968, Carl Yastrzemski led the American League with a .301 average.
Harmon Killebrew at .256.
San diego
Cal Ripken Jr. - 3,184 career base hits in a 21 season career (1981-2001) with a .276 lifetime batting average, the lowest of any current member of the 3,000 Hit Club.