Fergie and hubby Josh Duhamel took baby Axl to church with Fergie's mom Theresa on Mother's Day, enjoying every ounce of their sweet little boy on the special day.

The rocker mom was dressed in a colorful, short floral dress, a white blazer and heels; while dad Josh kept it casual in pants and a button-down. Little Axl wore ... well, what else -- a onsie!

Frankly, this trio could wear almost anything and still be at the top of our Hollywood's Cutest Family list!