The mother of three announced last month that she was set to depart from the station after 17 years in order to concentrate on family life.
Signing off from her lunchtime show she said: “If the pandemic has taught us anything, it's that we should all try to build a life that suits our personal definition of happiness.
"For so long, the thing that made me happy was my career here but that can change and that is definitely okay."
Mairead went on to thank all of her colleagues at Today FM, as well as her listeners for "making her dream come true."
She got emotional as she gave a shout out to her beloved children.
"Finally, I have to mention the three people who have forced me to make this big decision, my three beauties, the loves of my life - Dara, Eliza and Bonnie, I love you so much."
"God I feel like a wally now," she said through tears.
The final song she played on her show was Leave The Door Open by Bruno Mars.
Sharing the news of her departure with her lunchtime listeners back in November, Mairead said: “I have made an exciting but also a bittersweet decision I want to share. I’ve decided to step away from my lovely radio show.
"Radio and Today FM have made up such a large portion of my life, the people here are like family and presenting this show has been my highlight so it was really important to me that I get to share my news with you this way”.
“Like everyone in the country the last year has given me time to reflect on where I am in my life, what I’ve achieved and what I like to do and how I want to spend my time. Like everyone I was thrown into unexpected circumstances where my work and home life had to be looked at differently.”
“During all that chaos you’ll have heard me say it a lot, I found juggling work and home and all that went with stressful at times. But also in the middle of the madness my big takeaway and what showed up for me is that I really loved the simpler moments with the kids."
The mum of three said she realised that as life returned to "normal", she wanted to spend more time at home.
"It seems like the blink of an eye since Dara who is 14 was the age Eliza and Bonnie are now. I can’t believe it’s gone so quickly, so what I want to do is spend my time now relishing the everyday moments with them while they are small and spend time being the mum of a gorgeous teenager, something that’s new to me and I’m still trying to get used to!”
"As you can imagine I’ve spent a lot of time thinking about this, talking it through with my husband, Louis.
“I’ve been worried, nervous, scared and a whole heap of other emotions but once I made the decision, I knew it was the right time and the right move for me and I feel very fortunate to be able to make it. And really, I want to put into practice what I’ve learnt about myself over the last year”.
Mairead began presenting her own lunchtime show on Today FM in September 2019. Previously she worked on The Ian Dempsey Breakfast Show and got her start on the Ray D'Arcy show in 2004.
Mairead is currently the presenter on Ireland's Fittest Family on RTE One and previously appeared on the third season of Dancing with the Stars, which she won.