The survey reported by the Chicago Sun-Times Monday has the African-American state senator ahead 52 percent to 38 percent in the first poll taken since the March 16 primary. The poll of 806 likely voters statewide was conducted for Obama's campaign organization in late March.
The Illinois senate race could play a major role in determining which party controls the U.S. Senate in November.
Obama, 44, won a landslide victory in the primary over six Democratic candidates. Ryan, a 42-year-old millionaire investment banker-turned-high school teacher, won an eight-candidate race for the GOP nomination.
In a development that could affect the seven-month campaign, the Chicago Tribune and WLS-TV have asked a Los Angeles judge to make public Ryan's divorce records that were sealed at his request in 2001. Ryan and his actress wife, Jeri Ryan, ("Boston Public" and "Star Trek: Voyager") split in 1999.