Omaha has been a Royals' affiliate since 1969. The Storm Chasers also announced their new ownership group, Alliance Baseball Omaha LLC, on Tuesday.
Martie Cordaro, Omaha president and general manager since October 2011, said there was never any doubt that the clubs would extend the contract.
"In my 14 years of Minor League Baseball, I have never personally experienced such a great relationship with a Major League affiliate," Cordaro said. "We are excited to extend our partnership with the Royals."
In 2011, the Storm Chasers won the Pacific Coast League championship. They are currently in first place in the American North division with a 44-27 record.