As shown in the above video, the singer wore a red dress and black heels as the group performed "Silver Bells" and other Christmas favorites.
Fans quickly took to Twitter when the trio appeared on screen to compliment Scott's appearance and her vocal chops.
"Hillary Scott looks beautiful!" fan Tracy Boyer wrote.
Another added, "Lady Antebellum nailed it. Beautiful version of 'Silver Bells.'"
See some of the reactions below.
Hillary's adorable baby Bump!#CMAchristmas— stacey rains (@staceyrains5) November 28, 2017
Lady Antebullum nailed it. Beautiful version of SilverBells #CMAchristmas— Laura meholic (@laura_meholic) November 28, 2017
@HillaryScottLA You look amazing!!!— MzKristina (@sleepnbeauty115) November 28, 2017
I keep rewatching the videos of this performance,you guys were amazing and so mesmerizing! Keep it up!😊— JennaSSumner (@JennaSSumner) November 28, 2017
Photo Credit: ABC / Mark Levine