"They're doing business in Illinois. They should protect Illinois consumers," said the bill's sponsor, Sen. Ira Silverstein, D-Chicago.
The legislation, which passed 42-9, also would require dating services that say they conduct background checks to use government databases, including criminal court records and sex offender registries. In addition, the sites also would have to say whether they allow someone with a criminal record to sign up.
Furthermore, the legislation would require sites to post safety tips, including warnings that background checks aren't foolproof and suggestions to leave their addresses off the sites. Several companies already post this advice.
Sites that fail to follow the requirements or that lie about conducting background checks could face fines of up to $50,000 per violation.
Sen. Kwame Raoul, D-Chicago, voted against the bill, saying it stretches the government's influence too far.
"We're trying to legislate getting in people's dating patterns and their relationships and whether they use online dating and making sure that they're safe," he said. "We're not the mom and dad here in the legislature."
A former federal prosecutor, Sen. Darin LaHood, R-Dunlap, also opposed the measure, questioning whether the bill adequately addressed how to track companies outside of Illinois and enforce penalties.
The legislation now moves to the House, where a similar bill has won committee approval.
In other action, the Senate sent to the House bills to:
•Give employers tax breaks for hiring unemployed military veterans who have served since the Sept. 11, 2001, terrorist attacks.
•Require public schools to have annual inspections of driver's education cars that are at least 5 years old or have at least 75,000 miles.