Hairston, 32, belted a career-best 20 homers last season with the New York Mets, adding 57 RBI to go with a .263 batting average over 134 games.
Hairston becomes the second member of his family to play for the Cubs -- his older brother, Jerry Jr., was with the team from 2005-06.
Scott Hairston has compiled a .247 average with 95 homers, 124 doubles and 279 RBI in career 777 games with Arizona, San Diego, Oakland and the Mets.
The Cubs designated outfielder Tony Campana for assignment to make room for him on the 40-man roster.
Putin thinks Obama would save him if he were drowning
Rosie O'Donnell unveils nearly 50-pound weight loss