Oberman, 35, told supporters in an e-mail Monday that the treasurer's job is the right fit for his agenda of bringing reform to Illinois and creating jobs.
The treasurer's job will be open because first-term incumbent Alexi Giannoulias is giving up the post and running for President Barack Obama's old seat in the U.S. Senate.
Oberman's entry into the treasurer's race sets up a Democratic primary contest with Robin Kelly. Kelly is Giannoulias' chief of staff and a former state representative.
Among those encouraging him to run for Treasurer and endorsing his candidacy are former federal appeals court judge and congressman Abner Mikva and former U.S. Senator Adlai E. Stevenson III, according to a release on Oberman's Web site.
Oberman is the son of former Chicago Alderman Marty Oberman, who served the city's 43rd ward from 1975-1987. He made a brief run for the 5th congressional seat that was won by Mike Quigley.
Justin Oberman said he'll lay out his specific plans for the treasurer's office in the coming weeks.