Cue Card will end his career at Sandown on April 28.
Trainer Colin Tizzard and owner Jean Bishop had been in discussions over whether to bid for one more Grade One triumph in the Melling Chase at Aintree or the Grade Two bet365 Oaksey Chase at the Esher circuit.
But Bishop said: "We decided on Sandown. We just thought it would suit him because it tends to be a small field for that race and it gives him a bit longer with the prospect of some nice ground. It's the last day of the season, too, so it's a nice place for it all to come to an ending."
In the four years since its inception, the Oaksey Chase has been won only by the Philip Hobbs-trained Menorah, who himself retired after last season's victory.
Bishop added: "It's quite fitting he will end in a race that has only been won by Menorah, so far as he had quite a few good races against Menorah. Hopefully it will end the same way for us.
"He's been incredible. It makes no difference now but he wasn't even four when he won the Cheltenham Bumper - he was foaled at the end of April.
"Like them all he has had the odd problem in his career, but touch wood, he has come through them all without missing a lot."
Cue Card's jockey Paddy Brennan tweeted: " What a day in store @Sandownpark on the 28th of April. One last day out buddy. #cuecard #legend."