Terrero, 26, is hitting .231 (15-65) with four doubles, four home runs and nine RBI in 20 games with the Knights this season. He will wear uniform No. 30.
The 6-foot-3, 205-pounder split the 2006 season between Baltimore and Class AAA Ottawa. He appeared in 27 games with the Orioles, batting .200 (8-40) with one home run and six RBI.
Terrero has appeared in 182 games over four major-league seasons with Arizona (2003-05) and Baltimore (2006) and is a career .235 (102-434) hitter.
The White Sox 40-man roster now stands at 40.