Tomkat's baby.

A boy for Tom & Katie!

Katie Holmes has revealed the sex of her child after being spotted buying up big on blue baby clothes in LA recently.

Onlookers say the actress was shopping up a storm for her unborn son at the trendy Beverly Hills store Petit Bateau. Friends have reportedly confirmed the news, adding that Tom and Katie have already decided to call their baby boy William Oscar.

It’s unknown why the pair have chosen these names, although insiders note that Tom has an actor cousin named William Mapother.

Friends say the pair had also picked out the name Ella Elizabeth until it was confirmed they were expecting a boy.

There’s still no word on the bub’s due date, though given the size of Katie’s bump, insiders say it won’t be long.