The 40-year-old presenter stepped down from the show after she was arrested for allegedly assaulting her boyfriend at her London home.
She later took a step back from social media too but briefly returned to send a message ahead of the annual bash.
Posting on her Instagram story, Flack wrote on Tuesday (January 28) afternoon: “Good luck to all the team and cast at tonight’s NTAs.
“It’s such a fun night… cmon @loveisland.”
The current winter season of Love Island is being hosted by Flack’s friend Laura Whitmore.
The reality series is nominated for the Best Challenge Show award and will fo up against MasterChef, The Apprentice, The Circle and Great British Bake-Off.
Flack announced in December that she was stepping down from her role as Love Island presenter, a week after she was arrested for the alleged assault.
Flack is accused of hitting her boyfriend Lewis Burton, 27, over the head with a lamp while he was sleeping. She has denied the allegation.
Sharing the news of her resignation on her Instagram profile, Flack wrote: “There have been a significant number of media reports and allegations in regards to my personal life.
“While matters were not as have been reported, I am committed to co-operating with the appropriate authorities and I can’t comment further on these matters until the legal process is over.
“However, Love Island has been my world for the last five years, it’s the best show on telly. In order to not detract from the upcoming series I feel the best thing I can do is to stand down for series 6.
“I want to wish the incredible team working on the show a fantastic series in Cape Town.”
After entering a not guilty plea to the assault charge at Highbury Corner magistrate’s court, Flack was released on bail with conditions that forbid her from having contact with Burton ahead of her trial on March 4.