The 6-foot-1, 205-pound Jackson began the 2015 season with the Mariners, hitting .272 (114-419) in 107 games. He was traded to the Cubs on August 31 for a player to be named later. Jackson appeared in five postseason games with the Cubs, going 0-8 with a run scored.
"Austin provides us with another talented outfield option," said Rick Hahn, White Sox senior vice president/general manager. "His addition to the roster provides Robin with additional flexibility from both a defensive and offensive standpoint."
Jackson is a career .273 hitter (925-3,392) with 170 doubles, 47 triples, 55 home runs, 296 RBI, 522 runs scored, 106 stolen bases and a .333 on-base percentage in 860 games over six major-league seasons with Detroit (2010-14), Seattle (2014-15) and the Cubs (2015).
He won the 2010 Sporting News and Players Choice Rookie of the Year Awards after batting .293 (181-618) with 34 doubles, 10 triples, four homers and 41 RBI. Jackson also earned a Wilson AL Defensive Player Award in 2012-13.
Jackson hit 10-plus triples in each of his first three seasons, leading the AL in both 2011 (11) and 2012 (10). He has appeared in 40 career postseason games with the Tigers (2011-13) and Cubs (2015), batting .220 (31-141) with seven doubles, two homers and 11 RBI. Jackson helped Detroit reach the 2012 World Series.
Jackson originally was selected by the New York Yankees in the eighth round of the 2005 First-Year Player Draft. He was traded to the Tigers on December 8, 2009 as part of a three-team trade with Arizona that included Curtis Granderson, Edwin Jackson, Ian Kennedy and Max Scherzer. Jackson then was traded to the Mariners by Detroit as part of a three-team trade on July 31, 2014.
Olt, 27, batted .191 (18-94) with four home runs and five RBI in 30 games with the White Sox in 2015 after being claimed off waivers from the Cubs on September 5.
The White Sox 40-man roster remains at 40.