The mega-star spent most of his early years in Perthshire, attending Morrison’s Academy and working as a stagehand at Perth Theatre.
It is still unclear when the new baby will visit Scotland however, as the family currently divide their time between Los Angeles and London.
‘Welcome to the family little Laurie’
The new arrival was announced via a post on his big sister Clara’s Instagram page, with the caption reading: “Welcome to the world little brother congratulations to my Dad & Mary – this is the greatest gift.”
McGregor’s third daughter, Esther, added: “Welcome to the family little Laurie.”
As well as Clara Mathilde, 25, and Esther Rose, 19, McGregor has Jamyan, 20, and Anouk, 10, from his first marriage to production designer Eve Mavrakis.
Weanspotting – Perthshire native Ewan McGregor welcomes first baby with new partner