The 32-year-old comedian, best known alongside partner in crime Andy Lee, announced the couple's baby news on his radio show this afternoon.
"I'm having a baby with Zo," he said.
"That's a bit of big news."
The couple, who wed in December 2012, expect to welcome their first born in the new year.
Blake said he was not scared of the work involved in becoming a dad, but joked at the prospect of training the couple's cat, Meowbert, to change nappies.
In true Hamish style, the radio/TV personality shared this "ultrasound pic" on Twitter.