Sacha Baron Cohen & Isla Fisher Holy Moses ... It's A Boy!!

4/16/2015 4:00 PM PDT BY TMZ STAFF
EXCLUSIVE

 Sacha Baron Cohen Isla Fisher Baby Boy

Sacha Baron Cohen and Isla Fisher have made their first bouncing baby boy ... TMZ has learned.

We've obtained a copy of the birth certificate -- filed with the L.A. County Dept. of Public Health -- and it says Montgomery Moses Brian Baron Cohen was born on March 17.

It just came out last week they'd had the baby -- but they didn't say the name, sex or birth date.

MMBBC is the third child for Isla and the 'Borat' star. They have 2 daughters ... Olive, 7 and Elula, 4.

As for all the names, Isla's dad's name is Brian -- but we're at a loss on Montgomery and Moses ... outside of the 'Ten Commandments' guy.