Kyle's manager Bruno Bouchet later gave an update to Daily Mail Australia, saying: "Little Otto was born this morning. Mum and bub both doing well.
"Kyle's beyond excited. Kyle will be back on tomorrow's radio show to chat all things Otto."
Kyle first announced that he and his bride-to-be were expecting during his radio show in February, where he revealed that Tegan was three months along and the bub was set to arrive in August.
"We're having a baby!" Sandilands, 50, announced as the entire KIIS FM studio cheered.
WATCH: Kyle Sandilands proposes to Tegan Kynaston
The pair later announced they were expecting a boy after hosting a spectacular gender reveal on a boat, complete with planes flying over with blue smoke.
"Baby Sandilands is a….. BOY!! Congratulations Kyle and @tegankynaston on your little prince!" the KIIS FM Instagram page announced.
Kyle also told listeners of his show that they planned to give their bub a unique moniker.
“Otto, that’s what we’re going to call him,” Kyle, 50, said on-air.
“I don’t think it’s gone down well with the family, even Tegan’s mum goes ‘Well there’s no need to rush into a name’ and my auntie Jill went ‘Oh what sort of stupid name’s that?’”
Jackie O - who is mum to 10-year-old daughter Catalina 'Kitty' Henderson - went on to note that both she Kyle named their children after fine dining restaurants Catalina, in Rose Bay, and Otto, located at the finger wharf in Woolloomooloo.
“You know what I’ve realised? I’ve named my daughter Catalina as the restaurant Catalina and you’ve gone with Otto restaurant, we’re ensuring a lifetime of free food,” Jackie joked at the time.
Congratulations to the new parents!
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