MR. Big had to change his name over the weekend – to Mr. Big Daddy.

Chris Noth – the star of two diffrerent “Law & Order” shows as well as “Sex and the City” – and girlfriend Tara Wilson became parents on Friday night, according to reports.

Orion Christopher Noth was born in Los Angeles and weighed 7 lbs., 10 oz., said a spokesman.

“Chris and Tara are thrilled and all are doing well,” says the rep.

Wilson met the 53-year-old TV star while working at the New York bar he owns, The Cutting Room, in the Madison Square neighborhood.

Orion is the first baby for both parents.

According to reports last fall when Wilson’s pregnancy was first confirmed, the couple has no plans to marry.