Gov. Rod Blagojevich joined minimum wage workers to celebrate the increase Monday.
The change went into effect on Saturday.
Until the new year, thousands of workers in Illinois were paid $5.15 per hour.
Now, many dish washers, fast food employees and cashiers get an 18 percent raise, but Gov. Blagojevich says it's not enough.
Many opponents say it's bad for the economy because some business owners cannot afford the increase.
In Wisconsin, state legislators delayed voting on a minimum wage increase until December 2006.