Nearly 80 percent of hotel rooms were filled by visitors, the most in the city's history.
April's statistics are a sign that the tourism industry is back to pre-recession numbers.
Approximately 35,000 hotel rooms are available in the city, with more than 2,500 more under construction.
"I am committed to attracting visitors to Chicago, for business and pleasure," Mayor Rahm Emanuel was quoted in a city news release. "These numbers show a city that is moving in the right direction in this critical area and I look forward to welcoming more and more visitors to our wonderful city, and the positive economic impact they bring."
A recent campaign promoted what Chicago offers even during colder months.