"It's time to say goodbye and thank you," she wrote. "Half of my life spent in one place with wonderful people - friends, teachers and mentors.
"Thank you to every single person who tuned into TV3, More FM and Radio Live over the last 23 years. I know I wasn't everyone's cup of tea but to those who felt they had a friend in me, you did, just as I had a friend in you.
"Thank you for your kind words over the years and for the ticking off when I didn't get things right. I always listened to that advice too.
"Take care and for the last time from the news-desk tonight, Good evening."
But the post wasn't completely serious. It was accompanied by a montage of photos from Barry's time at the station, including one with her arm around Oprah Winfrey, another in which she pulled a funny face behind co-host Mike McRoberts, and a third cleaning her TV3 newsdesk with a rag.
In an interview with NZ Herald Focus, former TV3 sports presenter Hamish McKay called Barry's departure "ground zero" for the network.
"I can't even begin to imagine what it was like to be on the ground floor the day when that news filtered around," he said. "Someone like me leaving? Minor tremor. John Campbell? Earthquake. Hilary? Ground zero, tsunami."
Earlier today, Barry read the news on Paul Henry for the last time, with Henry paying her a quick tribute at the end of the show.
"Hilary, thank you very very much for the heart beats you've given to this show," Henry said.
"I've loved working with you ... we've laughed ... and we've laughed inappropriately."
Barry's departure, revealed by the Herald on April 29, is the second high-profile casualty at TV3 in the past year after John Campbell left last May when his show Campbell Live was dumped.
In a statement, Barry said she was "looking forward to recharging my batteries and spending more time with my family".