"This contract is the result of two sides coming together to put our students first," said Chicago Board of Education President David Vitale.
Nearly 80 percent of the Chicago Teachers Union's members voted to ratify the new contract earlier this month.
"Our campaign for a fair contract galvanized our members and has created a historic level of solidarity," said Karen Lewis, Chicago Teachers Union president.
CTU members voted to suspend a strike - the first one in 25 years - on September 18.
CPS - the nation's third largest school district - serves over 400,000 students in 681 schools.