This weekend on The iHeartRadio Countdown with Mario Lopez we've got a very special guest host filling in for Mario! The incredibly talented Niall Horan will be taking over the microphone! Mario is out, Niall is in and he's counting down the top 20 songs in the land! Plus Niall will be playing his new single 'Nice To Meet Ya', some of his favorite throwback songs and song other tracks from his catalog as well! This is going to be epic! Don't miss it!
Check out his latest music video right here!