Elite Sales will consign the filly for Bloom Racing, Madaket Stables and Allen Racing.
The 4YO daughter of Midnight Lute is currently undefeated in six starts in 2019 and has never finished off the board in 17 career outings, earning $US3,245,000.
"Very rarely is an in-form, young, set-to-be crowned champion offered at public auction," said Elite Sales' Bradley Weisbord.
In her most recent start Midnight Bisou won the GI Personal Ensign Stakes running down Elate in a dramatic stretch duel.
She has also won the GI Ogden Phipps, GI Apple Blossom, G2 Azeri Stakes, G3 Molly Pitcher and the G3 Houston Ladies Classic this season.
Last year at three, after breaking her maiden in the G2 Santa Ynez at Santa Anita, she rattled off wins in the G3 Santa Ysabel and GI Santa Anita Oaks while under the care of trainer Bill Spawr.
She then switched to the barn of Steve Asmussen and added the G2 Mother Goose Stakes and GI Cotillion Stakes and was placed in the G1 Coaching Club American Oaks, G1 Kentucky Oaks, G1 Alabama Stgakes and G1 Breeders' Cup Distaff.
Midnight Bisou is out of the G3 Florida Oaks winner Diva Delite (Repent) and was purchased by Jeff Bloom at the OBS April 2YOs in training sale in 2017 for $80,000.
"Midnight Bisou has truly been a dream come true for me, my family, and our partners," said Bloom. "She exemplifies class, beauty, and elegance, and she consistently displays unrivaled determination and dominance on the racetrack.
"She has taken us all on the ride of a lifetime and has forever changed our lives."