DNR Director Frank Jezioro said the trout was caught by Tony Corbin of Gerrardstown on May 2 from a private pond. The fish weighed 17.3 pounds.
Corbin used a swimbait on 10-pound test line to land the fish.
The previous weight record for a rainbow trout was a 15.65-pound fish set in 2005.
The length of the fish caught by Corbin was 30.5 inches. That fell short of the state record of 31.7 inches set in 1993.